@article {Roman2023a, title = {Current Perspectives on Securing Critical Infrastructures{\textquoteright} Supply Chains}, journal = {IEEE Security \& Privacy}, year = {In Press}, publisher = {IEEE}, issn = {1540-7993}, author = {Rodrigo Roman and Cristina Alcaraz and Javier Lopez and Kouichi Sakurai} } @article {MUNOZ2023103180, title = {A survey on the (in)security of Trusted Execution Environments}, journal = {Computers \& Security}, year = {2023}, pages = {103-180}, publisher = {Elsevier}, address = {In Press}, abstract = {

As the number of security and privacy attacks continue to grow around the world, there is an ever increasing need to protect our personal devices. As a matter of fact, more and more manufactures are relying on Trusted Execution Environments (TEEs) to shield their devices. In particular, ARM TrustZone (TZ) is being widely used in numerous embedded devices, especially smartphones, and this technology is the basis for secure solutions both in industry and academia. However, as shown in this paper, TEE is not bullet-proof and it has been successfully attacked numerous times and in very different ways. To raise awareness among potential stakeholders interested in this technology, this paper provides an extensive analysis and categorization of existing vulnerabilities in TEEs and highlights the design flaws that led to them. The presented vulnerabilities, which are not only extracted from existing literature but also from publicly available exploits and databases, are accompanied by some effective countermeasures to reduce the likelihood of new attacks. The paper ends with some appealing challenges and open issues.

}, keywords = {Computer security, Hardware attacks, Secure hardware, Side-channel attacks, Software attacks, Trusted Execution Environments}, issn = {0167-4048}, doi = {https://doi.org/10.1016/j.cose.2023.103180}, url = {https://www.sciencedirect.com/science/article/pii/S0167404823000901}, author = {Mu{\~n}oz, Antonio and Ruben Rios and Rodrigo Roman and Javier Lopez} } @inproceedings {2016, title = {AndroCIES: Automatizaci{\'o}n de la certificaci{\'o}n de seguridad para aplicaciones Android}, booktitle = {XVII Reuni{\'o}n Espa{\~n}ola sobre Criptolog{\'\i}a y Seguridad de la Informaci{\'o}n (RECSI 2022)}, volume = {265}, year = {2022}, month = {10/2022}, pages = {192-197}, publisher = {Ediciones Universidad Cantabria}, organization = {Ediciones Universidad Cantabria}, address = {Santander, Spain}, abstract = {

El auge de las plataformas m{\'o}viles est{\'a} impulsando el desarrollo de un gran n{\'u}mero de aplicaciones, muchas de las cuales salen al mercado sin las convenientes comprobaciones de seguridad. Recientemente, Google est{\'a} apostando por hacer este problema m{\'a}s visible y concienciar a los usuarios de la necesidad de instalar aplicaciones verificadas por laboratorios independientes. Sin embargo, la certificaci{\'o}n de aplicaciones suele ser una tarea ardua y no exenta de errores. Por ello, en este trabajo, presentamos la herramienta AndroCIES, que es capaz de automatizar en gran medida las evaluaciones necesarias para la certificaci{\'o}n de aplicaciones m{\'o}viles, reduciendo en torno a un 20\% el tiempo empleado en este proceso.

}, keywords = {an{\'a}lisis est{\'a}tico, aplicaciones, certificaci{\'o}n, seguridad}, author = {Manuel Ruiz and Ruben Rios and Rodrigo Roman and Mu{\~n}oz, Antonio and Juan Manuel Mart{\'\i}nez and Jorge Wallace} } @article {rios2022cpa, title = {Constrained Proximity Attacks on Mobile Targets}, journal = {ACM Transactions on Privacy and Security (TOPS)}, volume = {25}, number = {10}, year = {2022}, month = {05/2022}, pages = {1 - 29}, publisher = {Association for Computer Machinery (ACM)}, abstract = {

Proximity attacks allow an adversary to uncover the location of a victim by repeatedly issuing queries with fake location data. These attacks have been mostly studied in scenarios where victims remain static and there are no constraints that limit the actions of the attacker. In such a setting, it is not difficult for the attacker to locate a particular victim and quantifying the effort for doing so is straightforward. However, it is far more realistic to consider scenarios where potential victims present a particular mobility pattern. In this paper, we consider abstract (constrained and unconstrained) attacks on services that provide location information on other users in the proximity. We derive strategies for constrained and unconstrained attackers, and show that when unconstrained they can practically achieve success with theoretically optimal effort. We then propose a simple yet effective constraint that may be employed by a proximity service (for example, running in the cloud or using a suitable two-party protocol) as countermeasure to increase the effort for the attacker several orders of magnitude both in simulated and real-world cases.

}, keywords = {Location Privacy, mobility pattern, proximity attacks, quantification}, issn = {2471-2566}, doi = {10.1145/3498543}, author = {Xueou Wang and Xiaolu Hou and Ruben Rios and Nils Ole Tippenhauer and Martin Ochoa} } @article {rios2022pmec, title = {Personal IoT Privacy Control at the Edge}, journal = {IEEE Security \& Privacy }, volume = {20}, year = {2022}, month = {01/2022}, pages = {23 - 32}, publisher = {IEEE}, abstract = {

This article introduces a privacy manager for IoT data based on Edge Computing. This poses the advantage that privacy is enforced before data leaves the control of the user, who is provided with a tool to express data sharing preferences based on a novel context-aware privacy language.

}, issn = {1540-7993}, doi = {10.1109/MSEC.2021.3101865}, author = {Ruben Rios and Jose A. Onieva and Rodrigo Roman and Javier Lopez} } @inproceedings {1979, title = {Privacidad Contextual en entornos Edge}, booktitle = {VII Jornadas Nacionales de Investigaci{\'o}n en Ciberseguridad (JNIC 2022)}, year = {2022}, month = {06/2022}, pages = {122-129}, address = {Bilbao, Spain}, abstract = {

La privacidad contextual se refiere a la protecci{\'o}n de toda aquella informaci{\'o}n que puede desprenderse de la interacci{\'o}n entre usuarios y/o servicios, exceptuando los datos que el propio usuario elige transmitir. La localizaci{\'o}n, el tiempo, los patrones de uso y los diferentes par{\'a}metros necesarios para realizar la comunicaci{\'o}n son algunos ejemplos. Este tipo de privacidad es extremadamente importante en la computaci{\'o}n edge debido al acercamiento de los recursos de la infraestructura a los usuarios. Por ello, el objetivo de este trabajo es ofrecer un an{\'a}lisis y clasificaci{\'o}n de las diferentes soluciones propuestas en la literatura respecto a la privacidad contextual en entornos edge, mostrando tanto las capacidades de los mecanismos actuales como los desaf{\'\i}os en este campo.

}, keywords = {Computaci{\'o}n edge, Privacidad, Privacidad contextual}, isbn = {978-84-88734-13-6 }, author = {Manuel Ruiz and Ruben Rios and Rodrigo Roman and Javier Lopez} } @article {lopez2020, title = {Digital Twins for Intelligent Authorization in the B5G-enabled Smart Grid}, journal = {IEEE Wireless Communications}, volume = {28}, year = {2021}, month = {04/2021}, pages = {48-55}, publisher = {IEEE}, abstract = {

Beyond fifth generation (B5G) communication networks and computation paradigms in the edge are expected to be integrated into power grid infrastructures over the coming years. In this sense, AI technologies will play a fundamental role to efficiently manage dynamic information flows of future applications, which impacts the authorization policies applied in such a complex scenario. This article studies how digital twins can evolve their context awareness capabilities and simulation technologies to anticipate faults or to detect cyber-security issues in real time, and update access control policies accordingly. Our study analyzes the evolution of monitoring platforms and architecture decentralization, including the application of machine learning and blockchain technologies in the smart grid, toward the goal of implementing autonomous and self-learning agents in the medium and long term. We conclude this study with future challenges on applying digital twins to B5G-based smart grid deployments.

}, issn = {1536-1284}, doi = {https://doi.org/10.1109/MWC.001.2000336}, url = {https://ieeexplore.ieee.org/document/9430900}, author = {Javier Lopez and Juan E. Rubio and Cristina Alcaraz} } @article {Alcaraz2020a, title = {Blockchain-Assisted Access for Federated Smart Grid Domains: Coupling and Features}, journal = {Journal of Parallel and Distributed Computing}, volume = {144}, year = {2020}, month = {06/2020}, pages = {124-135}, publisher = {Elsevier}, issn = {0743-7315}, author = {Cristina Alcaraz and Juan E. Rubio and Javier Lopez} } @inproceedings {1846, title = {Distributed Detection of APTs: Consensus vs. Clustering}, booktitle = {25th European Symposium on Research in Computer Security (ESORICS 2020)}, volume = {12308}, year = {2020}, month = {09/2020}, pages = {174-192}, keywords = {Advanced Persistent Threat, clustering, consensus, distributed detection, Opinion Dynamics, Traceability}, isbn = {978-3-030-58951-6}, doi = {https://doi.org/10.1007/978-3-030-58951-6_9}, author = {Juan E. Rubio and Cristina Alcaraz and Ruben Rios and Rodrigo Roman and Javier Lopez} } @inproceedings {1840, title = {Game Theory-Based Approach for Defense against APTs}, booktitle = {18th International Conference on Applied Cryptography and Network Security (ACNS{\textquoteright}20)}, volume = {12147}, year = {2020}, month = {10/2020}, pages = {297-320}, publisher = {Springer}, organization = {Springer}, isbn = {978-3-030-57878-7}, doi = {https://doi.org/10.1007/978-3-030-57878-7_15}, author = {Juan E. Rubio and Cristina Alcaraz and Javier Lopez} } @article {Rubio2020IIoT, title = {Integration of a Threat Traceability Solution in the Industrial Internet of Things}, journal = {IEEE Transactions on Industrial Informatics}, volume = {16}, number = {6575-6583}, year = {2020}, month = {10/2020}, publisher = {IEEE}, abstract = {In Industrial Internet of Things (IIoT) scenarios, where a plethora of IoT technologies coexist with consolidated industrial infrastructures, the integration of security mechanisms that provide protection against cyber-security attacks becomes a critical challenge. Due to the stealthy and persistent nature of some of these attacks, such as Advanced Persistent Threats, it is crucial to go beyond traditional Intrusion Detection Systems for the traceability of these attacks. In this sense, Opinion Dynamics poses a novel approach for the correlation of anomalies, which has been successfully applied to other network security domains. In this paper, we aim to analyze its applicability in the IIoT from a technical point of view, by studying its deployment over different IIoT architectures and defining a common framework for the acquisition of data considering the computational constraints involved. The result is a beneficial insight that demonstrates the feasibility of this approach when applied to upcoming IIoT infrastructures. }, keywords = {Detection, Dynamics, IIoT, Industry, Intrusion, Opinion, Traceability}, issn = {1551-3203}, doi = {10.1109/TII.2020.2976747}, author = {Juan E. Rubio and Rodrigo Roman and Javier Lopez} } @article {rub2019cose, title = {Current Cyber-Defense Trends in Industrial Control Systems}, journal = {Computers \& Security Journal}, volume = {87}, year = {2019}, month = {11/2019}, publisher = {Elsevier}, type = {SECRYPT 2017 Special Issue}, abstract = {

Advanced Persistent Threats (APTs) have become a serious hazard for any critical infrastructure, as a single solution to protect all industrial assets from these complex attacks does not exist. It is then essential to understand what are the defense mechanisms that can be used as a first line of defense. For this purpose, this article will firstly study the spectrum of attack vectors that APTs can use against existing and novel elements of an industrial ecosystem. Afterwards, this article will provide an analysis of the evolution and applicability of Intrusion Detection Systems (IDS) that have been proposed in both the industry and academia.

}, keywords = {APT, Industrial Control, Industry 4.0, Intrusion Detection, SCADA}, issn = {0167-4048}, doi = {https://doi.org/10.1016/j.cose.2019.06.015}, author = {Juan E. Rubio and Cristina Alcaraz and Rodrigo Roman and Javier Lopez} } @article {HFNR2019, title = {Cybersecurity Profiles based on Human-Centric IoT Devices}, journal = {Human-centric Computing and Information Sciences}, volume = {9}, number = {1}, year = {2019}, pages = {1-23}, publisher = {Springer}, issn = {2192-1962}, doi = {10.1186/s13673-019-0200-y}, author = {Ana Nieto and Ruben Rios} } @article {onieva2019vec, title = {Edge-Assisted Vehicular Networks Security}, journal = {IEEE Internet of Things Journal}, volume = {6}, year = {2019}, month = {10/2019}, pages = {8038-8045}, publisher = {IEEE Computer Society}, abstract = {

Edge Computing paradigms are expected to solve some major problems affecting current application scenarios that rely on Cloud computing resources to operate. These novel paradigms will bring computational resources closer to the users and by doing so they will not only reduce network latency and bandwidth utilization but will also introduce some attractive context-awareness features to these systems. In this paper we show how the enticing features introduced by Edge Computing paradigms can be exploited to improve security and privacy in the critical scenario of vehicular networks (VN), especially existing authentication and revocation issues. In particular, we analyze the security challenges in VN and describe three deployment models for vehicular edge computing, which refrain from using vehicular- to-vehicular communications. The result is that the burden imposed to vehicles is considerably reduced without sacrificing the security or functional features expected in vehicular scenarios.

}, keywords = {Critical Infrastructures, Internet of Things, privacy, security, Vehicular Networks}, issn = {2327-4662}, doi = {10.1109/JIOT.2019.2904323}, author = {Jose A. Onieva and Ruben Rios and Rodrigo Roman and Javier Lopez} } @inproceedings {RubioESORICS2019, title = {Enhancing Security and Dependability of Industrial Networks with Opinion Dynamics}, booktitle = {European Symposium on Research in Computer Security (ESORICS2019)}, volume = {11736}, year = {2019}, month = {09/2019}, pages = {263-280}, doi = {https://doi.org/10.1007/978-3-030-29962-0_13}, author = {Juan E. Rubio and Mark Manulis and Cristina Alcaraz and Javier Lopez} } @article {roman2018VIS, title = {Immune System for the Internet of Things using Edge Technologies}, journal = {IEEE Internet of Things Journal}, volume = {6}, year = {2019}, month = {06/2019}, pages = {4774-4781}, publisher = {IEEE Computer Society}, abstract = {

The Internet of Things (IoT) and Edge Computing are starting to go hand in hand. By providing cloud services close to end-users, edge paradigms enhance the functionality of IoT deployments, and facilitate the creation of novel services such as augmented systems. Furthermore, the very nature of these paradigms also enables the creation of a proactive defense architecture, an immune system, which allows authorized immune cells (e.g., virtual machines) to traverse edge nodes and analyze the security and consistency of the underlying IoT infrastructure. In this article, we analyze the requirements for the development of an immune system for the IoT, and propose a security architecture that satisfies these requirements. We also describe how such a system can be instantiated in Edge Computing infrastructures using existing technologies. Finally, we explore the potential application of immune systems to other scenarios and purposes.

}, keywords = {Edge computing, Immune Systems, Internet of Things, security}, issn = {2327-4662}, doi = {10.1109/JIOT.2018.2867613}, url = {https://ieeexplore.ieee.org/document/8449989/}, author = {Rodrigo Roman and Ruben Rios and Jose A. Onieva and Javier Lopez} } @inproceedings {1835, title = {Personalized Computer Security Tasks with Automatic Evaluation and Feedback}, booktitle = {International Conference on Information Systems Education and Research (AIS SIGED 2019)}, year = {2019}, month = {12/2019}, keywords = {autonomy, evaluation, feedback, learn by doing, Moodle, self-learning}, isbn = {978-1-7343123-0-0}, author = {Isaac Agudo and Ruben Rios and Ana Nieto} } @incollection {1777, title = {Privacy-Aware Digital Forensics}, booktitle = {Security and Privacy for Big Data, Cloud Computing and Applications}, year = {2019}, month = {09/2019}, publisher = {The Institution of Engineering and Technology (IET) }, organization = {The Institution of Engineering and Technology (IET) }, edition = {Lizhe Wang, Wei Ren, Raymoond Choo and Fatos Xhafa}, address = {United Kingdom}, isbn = {978-1-78561-747-8}, url = {https://www.amazon.es/Security-Privacy-Computing-Applications-Networks/dp/1785617478}, author = {Ana Nieto and Ruben Rios and Javier Lopez} } @inproceedings {1815, title = {SealedGRID: A Secure Interconnection of Technologies for Smart Grid Applications}, booktitle = {14th International Conference on Critical Information Infrastructures Security (CRITIS 2019)}, volume = {11777}, year = {2019}, month = {12/2019}, pages = {169-175}, publisher = {Springer, Cham}, organization = {Springer, Cham}, abstract = {

In recent years, the Smart Grid has increasingly integrated cutting-edge technologies that generate several benefits for all the stakeholders involved, such as a more accurate billing system and enhanced Demand Response procedures. However, this modernization also brings with it diverse cyber security and privacy issues, which sets the necessity for developing a security platform specifically tailored to this scenario. In this paper, we present SealedGRID, which proposes a flexible architecture that provides security services at all levels by implementing Trusted Execution Environments on their devices, together with advanced authentication and authorization mechanisms, as well as privacy preserving techniques. These technologies are presented in depth and a final security analysis is conducted, which highlights the contributions of this project.

}, isbn = {978-3-030-37669-7}, doi = {https://doi.org/10.1007/978-3-030-37670-3_14}, author = {Aristeidis Farao and Juan E. Rubio and Cristina Alcaraz and Christoforos Ntantogian and Christos Xenakis and Javier Lopez} } @article {RubioSIJCS19, title = {Tracking APTs in Industrial Ecosystems: A Proof of Concept}, journal = {Journal of Computer Security}, volume = {27}, year = {2019}, month = {09/2019}, pages = {521-546}, publisher = {Elsevier}, type = {ESORICS 2018 Special Issue }, issn = {0167-4048}, author = {Juan E. Rubio and Rodrigo Roman and Cristina Alcaraz and Yan Zhang} } @article {LOPEZ201846, title = {Access control for cyber-physical systems interconnected to the cloud}, journal = {Computer Networks}, volume = {134}, year = {2018}, pages = {46 - 54}, publisher = {Elsevier}, keywords = {Access, Cloud, Control, Cyber, Physical, security, Systems}, issn = {1389-1286}, doi = {https://doi.org/10.1016/j.comnet.2018.01.037}, url = {http://www.sciencedirect.com/science/article/pii/S1389128618300501}, author = {Javier Lopez and Juan E. Rubio} } @inproceedings {1692, title = {Addressing Security in OCPP: Protection Against Man-in-the-Middle Attacks}, booktitle = {9th IFIP International Conference on New Technologies, Mobility \& Security}, year = {2018}, author = {Juan E. Rubio and Cristina Alcaraz and Javier Lopez} } @inproceedings {1666, title = {Analysis of cybersecurity threats in Industry 4.0: the case of intrusion detection}, booktitle = {The 12th International Conference on Critical Information Infrastructures Security}, volume = {Lecture Notes in Computer Science, vol 10707}, year = {2018}, month = {08/2018}, pages = {119-130}, publisher = {Springer}, organization = {Springer}, author = {Juan E. Rubio and Rodrigo Roman and Javier Lopez} } @proceedings {rios2018dpm, title = {Data Privacy Management, Cryptocurrencies and Blockchain Technology}, volume = {11025}, year = {2018}, publisher = {Springer International Publishing}, edition = {LNCS}, address = {Barcelona, Spain}, abstract = {

ESORICS 2018 International Workshops, DPM 2018 and CBT 2018, Barcelona, Spain, September 6-7, 2018, Proceedings

}, isbn = {978-3-030-00305-0}, doi = {10.1007/978-3-030-00305-0}, author = {Joaquin Garcia-Alfaro and Jordi Herrera-Joancomarti and Giovanni Livraga and Ruben Rios} } @article {RomanIoT18, title = {Evolution and Trends in the Security of the Internet of Things}, journal = {IEEE Computer}, volume = {51}, year = {2018}, month = {07/2018}, pages = {16-25}, publisher = {IEEE Computer Society}, address = {New Jersey, USA}, keywords = {Evolution, Internet of Things, IoT, security, Trends}, issn = {0018-9162}, doi = {10.1109/MC.2018.3011051}, url = {https://ieeexplore.ieee.org/document/8423133/}, author = {Rodrigo Roman and Javier Lopez and Stefanos Gritzalis} } @article {Hiroshi18IoT, title = {Feasibility of Societal Model for Securing Internet of Things}, journal = {KSII Transactions on Internet and Information Systems}, volume = {12}, number = {8}, year = {2018}, month = {08/2018}, pages = {3567-3588}, publisher = {KSII}, abstract = {

In the Internet of Things (IoT) concept, devices communicate autonomously with applications in the Internet. A significant aspect of IoT that makes it stand apart from present-day networked devices and applications is a) the very large number of devices, produced by diverse makers and used by an even more diverse group of users; b) the applications residing and functioning in what were very private sanctums of life e.g. the car, home, and the people themselves. Since these diverse devices require high-level security, an operational model for an IoT system is required, which has built-in security. We have proposed the societal model as a simple operational model. The basic concept of the model is borrowed from human society {\textendash} there will be infants, the weak and the handicapped who need to be protected by guardians. This natural security mechanism works very well for IoT networks which seem to have inherently weak security mechanisms. In this paper, we discuss the requirements of the societal model and examine its feasibility by doing a proof-of-concept implementation.

}, keywords = {Internet of Things, IoT, network architecture, operational model, security, SNMP}, issn = {1976-7277}, doi = {10.3837/tiis.2018.08.003}, url = {http://www.itiis.org/digital-library/manuscript/2082}, author = {Hiroshi Tsunoda and Rodrigo Roman and Javier Lopez and Glenn Mansfield Keeni} } @article {nrlSensors2018, title = {IoT-Forensics meets Privacy: Towards Cooperative Digital Investigations}, journal = {Sensors}, volume = {18}, number = {492}, year = {2018}, month = {02/2018}, publisher = {MDPI}, abstract = {
IoT-Forensics is a novel paradigm for the acquisition of electronic evidence whose operation is conditioned by the peculiarities of the Internet of Things (IoT) context. As a branch of computer forensics, this discipline respects the most basic forensic principles of preservation, traceability, documentation, and authorization. The digital witness approach also promotes such principles in the context of the IoT while allowing personal devices to cooperate in digital investigations by voluntarily providing electronic evidence to the authorities. However, this solution is highly dependent on the willingness of citizens to collaborate and they may be reluctant to do so if the sensitive information within their personal devices is not sufficiently protected when shared with the investigators. In this paper, we provide the digital witness approach with a methodology that enables citizens to share their data with some privacy guarantees. We apply the PRoFIT methodology, originally defined for IoT-Forensics environments, to the digital witness approach in order to unleash its full potential. Finally, we show the feasibility of a PRoFIT-compliant digital witness with two use cases.
}, keywords = {digital witness, IoT-Forensics, privacy}, issn = {1424-8220}, doi = {10.3390/s18020492}, url = {http://www.mdpi.com/1424-8220/18/2/492}, author = {Ana Nieto and Ruben Rios and Javier Lopez} } @inproceedings {rios2018mob, title = {Location Proximity Attacks against Mobile Targets: Analytical Bounds and Attacker Strategies}, booktitle = {23rd European Symposium on Research in Computer Security (ESORICS 2018)}, series = {LNCS}, volume = {11099}, year = {2018}, pages = {373-392}, publisher = {Springer}, organization = {Springer}, address = {Barcelona}, abstract = {

Location privacy has mostly focused on scenarios where users remain static. However, investigating scenarios where the victims present a particular mobility pattern is more realistic. In this paper, we consider abstract attacks on services that provide location information on other users in the proximity. In that setting, we quantify the required effort of the attacker to localize a particular mobile victim. We prove upper and lower bounds for the effort of an optimal attacker. We experimentally show that a Linear Jump Strategy\ (LJS) practically achieves the upper bounds for almost uniform initial distributions of victims. To improve performance for less uniform distributions known to the attacker, we propose a Greedy Updating Attack Strategy\ (GUAS). Finally, we derive a realistic mobility model from a real-world dataset and discuss the performance of our strategies in that setting.

}, isbn = {978-3-319-98988-4}, doi = {10.1007/978-3-319-98989-1}, author = {Xueou Wang and Xiaolu Hou and Ruben Rios and Per Hallgren and Nils Ole Tippenhauer and Martin Ochoa} } @article {RomanFog16, title = {Mobile edge computing, Fog et al.: A survey and analysis of security threats and challenges}, journal = {Future Generation Computer Systems}, volume = {78}, year = {2018}, month = {01/2018}, pages = {680-698}, publisher = {Elsevier}, abstract = {

For various reasons, the cloud computing paradigm is unable to meet certain requirements (e.g. low latency and jitter, context awareness, mobility support) that are crucial for several applications (e.g. vehicular networks, augmented reality). To fulfil these requirements, various paradigms, such as fog computing, mobile edge computing, and mobile cloud computing, have emerged in recent years. While these edge paradigms share several features, most of the existing research is compartmentalised; no synergies have been explored. This is especially true in the field of security, where most analyses focus only on one edge paradigm, while ignoring the others. The main goal of this study is to holistically analyse the security threats, challenges, and mechanisms inherent in all edge paradigms, while highlighting potential synergies and venues of collaboration. In our results, we will show that all edge paradigms should consider the advances in other paradigms.

}, keywords = {Cloud Computing, Fog computing, Mobile cloud computing, Mobile edge computing, privacy, security}, issn = {0167-739X}, doi = {10.1016/j.future.2016.11.009}, url = {https://authors.elsevier.com/c/1VmhQ,3q5xKgZZ}, author = {Rodrigo Roman and Javier Lopez and Masahiro Mambo} } @article {Ruben2017trust, title = {Modelling Privacy-Aware Trust Negotiations}, journal = {Computers \& Security}, volume = {77 }, year = {2018}, pages = {773-789}, publisher = {Elsevier}, abstract = {

Trust negotiations are mechanisms that enable interaction between previously unknown users. After exchanging various pieces of potentially sensitive information, the participants of a negotiation can decide whether or not to trust one another. Therefore, trust negotiations bring about threats to personal privacy if not carefully considered. This paper presents a framework for representing trust negotiations in the early phases of the Software Development Life Cycle (SDLC). The framework can help software engineers to determine the most suitable policies for the system by detecting conflicts between privacy and trust requirements. More precisely, we extend the SI* modelling language and provide a set of predicates for defining trust and privacy policies and a set of rules for describing the dynamics of the system based on the established policies. The formal representation of the model facilitates its automatic verification. The framework has been validated in a distributed social network scenario for connecting drivers with potential passengers willing to share a journey.

}, keywords = {Goal-Oriented Modelling, Policy, privacy, Requirements Engineering, Secure Software Engineering, Trust}, issn = {0167-4048}, doi = {10.1016/j.cose.2017.09.015}, author = {Ruben Rios and Carmen Fernandez-Gago and Javier Lopez} } @article {transactionInformaticsSG2018, title = {A Resilient Architecture for the Smart Grid}, journal = {IEEE Transactions on Industrial Informatics}, volume = {14}, year = {2018}, month = {08/2019}, pages = {3745-3753}, publisher = {IEEE}, type = {Journal}, abstract = {

The Smart Grid offers many benefits due to the bidirectional communication between the users and the utility company, which makes it possible to perform a fine-grain consumption metering. This can be used for Demand Response purposes with the generation and delivery of electricity in real time. It is essential to rapidly anticipate high peaks of demand or potential attacks, so as to avoid power outages and denial of service, while effectively supplying consumption areas. In this paper, we propose a novel architecture where cloud computing resources are leveraged (and tested in practice) to enable, on the one hand, the consumption prediction through time series forecasting, as well as load balancing to uniformly distribute the demand over a set of available generators. On the other and,\ it also allows the detection of connectivity losses and intrusions within the control network by using controllability concepts.

}, issn = {1551-3203}, doi = {10.1109/TII.2018.2826226}, author = {Javier Lopez and Juan E. Rubio and Cristina Alcaraz} } @inproceedings {RubioRomanAlcarazZhang2018, title = {Tracking Advanced Persistent Threats in Critical Infrastructures through Opinion Dynamics}, booktitle = {European Symposium on Research in Computer Security (ESORICS 2018)}, volume = {11098}, year = {2018}, month = {08/2018}, pages = {555-574}, publisher = {Springer}, organization = {Springer}, address = {Barcelona, Spain}, abstract = {

Advanced persistent threats pose a serious issue for modern industrial environments, due to their targeted and complex attack vectors that are difficult to detect. This is especially severe in critical infrastructures that are accelerating the integration of IT technologies. It is then essential to further develop effective monitoring and response systems that ensure the continuity of business to face the arising set of cyber-security threats. In this paper, we study the practical applicability of a novel technique based on opinion dynamics, that permits to trace the attack throughout all its stages along the network by correlating different anomalies measured over time, thereby taking the persistence of threats and the criticality of resources into consideration. The resulting information is of essential importance to monitor the overall health of the control system and correspondingly deploy accurate response procedures.

}, keywords = {Advanced Persistent Threat, Detection, Opinion Dynamics, Traceability}, doi = {10.1007/978-3-319-99073-6_27}, url = {https://link.springer.com/chapter/10.1007/978-3-319-99073-6_27}, author = {Juan E. Rubio and Rodrigo Roman and Cristina Alcaraz and Yan Zhang} } @inproceedings {1662, title = {Analysis of Intrusion Detection Systems in Industrial Ecosystems}, booktitle = {14th International Conference on Security and Cryptography (SECRYPT 2017)}, volume = {6}, year = {2017}, pages = {116-128}, publisher = {SciTePress}, organization = {SciTePress}, isbn = {978-989-758-259-2}, doi = {10.5220/0006426301160128}, author = {Juan E. Rubio and Cristina Alcaraz and Rodrigo Roman and Javier Lopez} } @inproceedings {1654, title = {Digital Witness and Privacy in IoT: Anonymous Witnessing Approach}, booktitle = {16th IEEE International Conference On Trust, Security And Privacy In Computing And Communications (TrustCom 2017)}, year = {2017}, month = {08/2017}, pages = {642-649}, publisher = {IEEE}, organization = {IEEE}, address = {Sydney (Australia)}, abstract = {

The digital witness approach defines the collaboration between IoT devices - from wearables to vehicles - to provide digital evidence through a Digital Chain of Custody to an authorised entity. As one of the cores of the digital witness, binding credentials unequivocally identify the user behind the digital witness. The objective of this article is to perform a critical analysis of the digital witness approach from the perspective of privacy, and to propose solutions that help include some notions of privacy in the scheme (for those cases where it is possible). In addition, digital anonymous witnessing as a tradeoff mechanism between the original approach and privacy requirements is proposed. This is a clear challenge in this context given the restriction that the identities of the links in the digital chain of custody should be known.\ 

}, keywords = {Forensics, IEC Standards, ISO Standards, privacy}, isbn = {978-1-5090-4906-6}, issn = {2324-9013}, doi = {10.1109/Trustcom/BigDataSE/ICESS.2017.295}, author = {Ana Nieto and Ruben Rios and Javier Lopez} } @inproceedings {1653, title = {Estado y Evoluci{\'o}n de la Detecci{\'o}n de Intrusiones en los Sistemas Industriales}, booktitle = {III Jornadas Nacionales de Investigaci{\'o}n en Ciberseguridad (JNIC 2017)}, year = {2017}, abstract = {

Debido a la necesidad de proteger los sistemas\ industriales ante amenazas, se hace necesario comprender cual\ es el verdadero alcance de los mecanismos capaces de detectar\ potenciales anomal{\'\i}as e intrusiones. Es por tanto el objetivo de\ este art{\'\i}culo analizar el estado y la evoluci{\'o}n, tanto acad{\'e}mica\ como industrial, de los mecanismos de detecci{\'o}n de intrusiones\ en este campo, as{\'\i}\ como estudiar su aplicabilidad actual y futura.

}, author = {Cristina Alcaraz and Jes{\'u}s Rodriguez and Roman, Rodrigo and Juan E. Rubio} } @article {Lopez2017iotpriv, title = {Evolving privacy: From sensors to the Internet of Things}, journal = {Future Generation Computer Systems}, volume = {75}, year = {2017}, month = {10/2017}, pages = {46{\textendash}57}, publisher = {Elsevier}, abstract = {

The Internet of Things (IoT) envisions a world covered with billions of smart, interacting things capable of offering all sorts of services to near and remote entities. The benefits and comfort that the IoT will bring about are undeniable, however, these may come at the cost of an unprecedented loss of privacy. In this paper we look at the privacy problems of one of the key enablers of the IoT, namely wireless sensor networks, and analyse how these problems may evolve with the development of this complex paradigm. We also identify further challenges which are not directly associated with already existing privacy risks but will certainly have a major impact in our lives if not taken into serious consideration.\ 

}, keywords = {Challenges, Internet of Things, privacy, WSN}, issn = {0167-739X}, doi = {10.1016/j.future.2017.04.045}, author = {Javier Lopez and Ruben Rios and Feng Bao and Guilin Wang} } @inproceedings {Ruben2017smog, title = {From Smog to Fog: A Security Perspective}, booktitle = {2nd IEEE International Conference on Fog and Edge Mobile Computing (FMEC 2017)}, year = {2017}, month = {06/2017}, pages = {56-61}, publisher = {IEEE Computer Society}, organization = {IEEE Computer Society}, address = {Valencia, Spain. 8-11 May 2017}, abstract = {

Cloud computing has some major limitations that hinder its application to some specific scenarios (e.g., Industrial IoT, and remote surgery) where there are particularly stringent requirements, such as extremely low latency. Fog computing is a specialization of the Cloud that promises to overcome the aforementioned limitations by bringing the Cloud closer to end-users. Despite its potential benefits, Fog Computing is still a developing paradigm which demands further research, especially on security and privacy aspects. This is precisely the focus of this paper: to make evident the urgent need for security mechanisms in Fog computing, as well as to present a research strategy with the necessary steps and processes that are being undertaken within the scope of the SMOG project, in order to enable a trustworthy and resilient Fog ecosystem.

}, isbn = {978-1-5386-2859-1}, doi = {10.1109/FMEC.2017.7946408}, author = {Ruben Rios and Rodrigo Roman and Jose A. Onieva and Javier Lopez} } @inproceedings {1652, title = {A Methodology for Privacy-Aware IoT-Forensics}, booktitle = {16th IEEE International Conference On Trust, Security And Privacy In Computing And Communications (TrustCom 2017)}, year = {2017}, month = {08/2017}, pages = {626-633}, publisher = {IEEE}, organization = {IEEE}, address = {Sydney (Australia)}, abstract = {

The Internet of Things (IoT) brings new challenges to digital forensics. Given the number and heterogeneity of devices in such scenarios, it bring extremely difficult to carry out investigations without the cooperation of individuals. Even if they are not directly involved in the offense, their devices can yield digital evidence that might provide useful clarification in an investigation. However, when providing such evidence they may leak sensitive personal information. This paper proposes PRoFIT; a new model for IoT-forensics that takes privacy into consideration by incorporating the requirements of ISO/IEC 29100:2011 throughout the investigation life cycle. PRoFIT is intended to lay the groundwork for the voluntary cooperation of individuals in cyber crime investigations.

}, keywords = {Adaptation models, Forensics, IEC Standards, Information management, ISO Standards, privacy, Software}, isbn = {978-1-5090-4906-6}, issn = {2324-9013}, doi = {10.1109/Trustcom/BigDataSE/ICESS.2017.293}, author = {Ana Nieto and Ruben Rios and Javier Lopez} } @inproceedings {RubioAlcarazLopez2017ESORICS, title = {Preventing Advanced Persistent Threats in Complex Control Networks}, booktitle = {European Symposium on Research in Computer Security}, volume = {10493}, year = {2017}, month = {09/2017}, pages = {402-418}, publisher = {22nd European Symposium on Research in Computer Security (ESORICS 2017)}, organization = {22nd European Symposium on Research in Computer Security (ESORICS 2017)}, author = {Juan E. Rubio and Cristina Alcaraz and Javier Lopez} } @inproceedings {1655, title = {PRoFIT: modelo forense-IoT con integraci{\'o}n de requisitos de privacidad}, booktitle = {XIII Jornadas de Ingenier{\'\i}a Telem{\'a}tica (JITEL 2017)}, volume = {Libro de actas}, year = {2017}, month = {01/2018}, pages = {302-309}, publisher = {Editorial Universitat Polit{\`e}cnica de Val{\`e}ncia}, organization = {Editorial Universitat Polit{\`e}cnica de Val{\`e}ncia}, address = {Valencia}, isbn = {978-84-9048-595-8}, doi = {http://dx.doi.org/10.4995/JITEL2017.2017.7061}, url = {http://jlloret.webs.upv.es/jitel2017/files/ACTASJITEL2017.pdf}, author = {Ana Nieto and Ruben Rios and Javier Lopez} } @article {lopez2017ecn, title = {Protecting Industry 4.0 against Advanced Persistent Threats}, journal = {European CIIP Newsletter}, volume = {11}, number = {1}, year = {2017}, month = {03/2017}, pages = {27-29}, publisher = {European CIIP Newsletter}, issn = {NONE}, author = {Javier Lopez and Cristina Alcaraz and Jes{\'u}s Rodriguez and Rodrigo Roman and Juan E. Rubio} } @inproceedings {Rios2017query, title = {Query Privacy in Sensing-as-a-Service Platforms}, booktitle = {32nd International Conference on ICT Systems Security and Privacy Protection (IFIP SEC 2017)}, series = {IFIP Advances in Information and Communication Technology (AICT)}, volume = {502}, year = {2017}, month = {05/2017}, pages = {141{\textendash}154}, publisher = {Springer}, organization = {Springer}, address = {Roma, Italy}, abstract = {

The Internet of Things (IoT) promises to revolutionize the way we interact with the physical world. Even though this paradigm is still far from being completely realized, there already exist Sensing-as-a-Service (S2aaS) platforms that allow users to query for IoT data. While this model offers tremendous benefits, it also entails increasingly challenging privacy issues. In this paper, we concentrate on the protection of user privacy when querying sensing devices through a semi-trusted S2aaS platform. In particular, we build on techniques inspired by proxy re-encryption and k-anonymity to tackle two intertwined problems, namely query privacy and query confidentiality. The feasibility of our solution is validated both analytically and empirically.\ 

}, doi = {10.1007/978-3-319-58469-0_10}, author = {Ruben Rios and David Nu{\~n}ez and Javier Lopez}, editor = {Sabrina De Capitani di Vimercati and Fabio Martinelli} } @article {rubiorecommender17, title = {Recommender System for Privacy-Preserving Solutions in Smart Metering}, journal = {Pervasive and Mobile Computing}, volume = {41}, year = {2017}, month = {10/2017}, pages = {205-218}, publisher = {Pervasive and Mobile Computing}, abstract = {

Nowadays, Smart Grid is envisaged to provide several benefits to both customers and grid operators. However, Smart Meters introduce many privacy issues if consumption data is analysed. In this paper we analyse the main techniques that address privacy when collecting electricity readings. In addition to privacy, it is equally important to preserve efficiency to carry on with monitoring operations, so further control requirements and communication protocols are also studied. Our aim is to provide guidance to installers who intend to integrate such mechanisms on the grid, presenting an expert system to recommend an appropriate deployment strategy.

}, issn = {1574-1192}, author = {Juan E. Rubio and Cristina Alcaraz and Javier Lopez} } @inproceedings {1648, title = {Requisitos y soluciones de privacidad para la testificaci{\'o}n digital}, booktitle = {III Jornadas Nacionales de Investigaci{\'o}n en Ciberseguridad (JNIC 2017)}, volume = {Actas del JNIC 2017}, year = {2017}, pages = {51-58}, publisher = { Servicio de Publicaciones de la URJC}, organization = { Servicio de Publicaciones de la URJC}, address = {Madrid (Spain)}, isbn = {978-84-608-4659-8}, url = {https://eciencia.urjc.es/handle/10115/14540}, author = {Ana Nieto and Ruben Rios} } @inproceedings {1600, title = {Selecting Privacy Solutions to Prioritise Control in Smart Metering Systems}, booktitle = {The 11th International Conference on Critical Information Infrastructures Security}, volume = {10242}, year = {2017}, pages = {176-188}, abstract = {

The introduction of the Smart Grid brings with it several benefits to society, because its bi-directional communication allows both users and utilities to have better control over energy usage. However, it also has some privacy issues with respect to the privacy of the customers when analysing their consumption data. In this paper we review the main privacy-preserving techniques that have been proposed and compare their efficiency, to accurately select the most appropriate ones for undertaking control operations. Both privacy and performance are essential for the rapid adoption of Smart Grid technologies.

}, keywords = {and Metering, Control, Data privacy, Smart Grid}, author = {Juan E. Rubio and Cristina Alcaraz and Javier Lopez} } @inproceedings {1582, title = {Arquitectura funcional para la cadena de custodia digital en objetos de la IoT}, booktitle = {XIV Reuni{\'o}n Espa{\~n}ola sobre Criptolog{\'\i}a y Seguridad de la Informaci{\'o}n}, year = {2016}, month = {10/2016}, pages = {168-173}, abstract = {
En la Internet de los Objetos (IoT, por sus siglas en ingl{\'e}s), los ataques pueden ser perpetrados desde dispositivos que enmascaran su rastro ayud{\'a}ndose de la densidad de objetos y usuarios. Actualmente la idea de que los dispositivos de usuario almacenan evidencias que pueden ser muy valiosas para frenar ataques es bien conocida. Sin embargo, la colaboraci{\'o}n de {\'e}stos para denunciar posibles abusos telem{\'a}ticos a{\'u}n est{\'a} por definir. Los testigos digitales son dispositivos concebidos para definir la participaci{\'o}n de dispositivos de usuario en una cadena de custodia digital. La idea es que las evidencias se generan, almacenan y transfieren siguiendo los requisitos marcados por las normas actuales (p.ej. UNE 71505), pero respetando las restricciones en recursos de los dispositivos. En este art{\'\i}culo proponemos una arquitectura funcional para la implementaci{\'o}n del concepto de testigo digital en dispositivos heterog{\'e}neos de la IoT.
}, keywords = {Cadena de custodia digital, Identidad de las cosas, Testigo digital}, isbn = {978-84-608-9470-4}, author = {Ana Nieto and Rodrigo Roman and Javier Lopez} } @article {ercim-nrl16, title = {Digital Witness: Digital Evidence Management Framework for the Internet of Things}, journal = {ERCIM News}, number = {106}, year = {2016}, month = {07/2016}, pages = {9-9}, publisher = {ERCIM EEIG}, issn = {0926-4981}, url = {http://ercim-news.ercim.eu/images/stories/EN106/EN106-web.pdf}, author = {Ana Nieto and Rodrigo Roman and Javier Lopez} } @article {ieeenet16-nrl, title = {Digital Witness: Safeguarding Digital Evidence by using Secure Architectures in Personal Devices}, journal = {IEEE Network}, year = {2016}, pages = {12-19}, publisher = {IEEE Communications Society}, abstract = {

Personal devices contain electronic evidence associated with the behaviour of their owners and other devices in their environment, which can help clarify the facts of a cyber-crime scene. These devices are usually analysed as containers of proof. However, it is possible to harness the boom of personal devices to define the concept of digital witnesses, where personal devices are able to actively acquire, store, and transmit digital evidence to an authorised entity, reliably and securely. This article introduces this novel concept, providing a preliminary analysis on the management of digital evidence and the technologies that can be used to implement it with security guarantees in IoT environments. Moreover, the basic building blocks of a digital witness are defined.

}, keywords = {Digital Evidence, Identity Delegation, IoT-Forensics, Secure Element}, issn = {0890-8044}, doi = {10.1109/MNET.2016.1600087NM}, url = {http://ieeexplore.ieee.org/document/7764297/$\#$full-text-section}, author = {Ana Nieto and Rodrigo Roman and Javier Lopez} } @inproceedings {Rios2016a, title = {Evoluci{\'o}n y nuevos desafios de privacidad en la Internet de las Cosas}, booktitle = {XIV Reuni{\'o}n Espa{\~n}ola sobre Criptolog{\'\i}a y Seguridad de la Informaci{\'o}n}, year = {2016}, month = {10/2016}, pages = {209-213}, address = {Mah{\'o}n, Menorca, Islas Baleares}, abstract = {

La Internet de las Cosas (en ingl{\'e}s, Internet of Things\ (IoT)) es una evoluci{\'o}n de la Internet tal y como lo conocemos. Esta nueva versi{\'o}n de Internet incorpora objetos de la vida cotidiana, rompiendo as{\'\i} barrera de los digital y extendi{\'e}ndose al mundo f{\'\i}sico. Estos objetos interactuar{\'a}n entre s{\'\i} y con otras entidades tanto de manera local como remota, y estar{\'a}n dotados de cierta capacidad computacional y sensores para que sean conscientes de lo que ocurre en su entorno. Esto traer{\'a} consigo un sinf{\'\i}n de posibilidades y nuevos servicios, pero tambi{\'e}n dar{\'a} lugar a nuevos y mayores riesgos de privacidad para los ciudadanos. En este art{\'\i}culo, estudiamos los problemas de privacidad actuales de una de las tecnolog{\'\i}as claves para el desarrollo de este prometedor paradigma, las redes de sensores, y analizamos como pueden evolucionar y surgir nuevos riesgos de privacidad al ser completamente integradas en la Internet.

}, keywords = {Challenges, Internet of Things, privacy, Sensors}, author = {Ruben Rios and Javier Lopez} } @book {Rios2016, title = {Location Privacy in Wireless Sensor Networks}, series = {CRC Series in Security, Privacy and Trust}, year = {2016}, publisher = {Taylor \& Francis}, organization = {Taylor \& Francis}, isbn = {9781498776332}, url = {https://www.crcpress.com/Location-Privacy-in-Wireless-Sensor-Networks/Rios-Lopez-Cuellar/p/book/9781498776332}, author = {Ruben Rios and Javier Lopez and Jorge Cuellar} } @inproceedings {rios2016b, title = {Privacy-Aware Trust Negotiation}, booktitle = {12th International Workshop on Security and Trust Management (STM)}, volume = {LNCS 9871}, year = {2016}, month = {09/2016}, pages = {98-105}, publisher = {Springer}, organization = {Springer}, address = {Heraklion, Crete, Greece}, abstract = {

Software engineering and information security have traditionally followed divergent paths but lately some efforts have been made to consider security from the early phases of the Software Development Life Cycle (SDLC). This paper follows this line and concentrates on the incorporation of trust negotiations during the requirements engineering phase. More precisely, we provide an extension to the SI* modelling language, which is further formalised using answer set programming specifications to support the automatic verification of the model and the detection of privacy conflicts caused by trust negotiations.

}, keywords = {Goal-Oriented Modelling, privacy, Requirements Engineering, Secure Software Engineering, Trust}, isbn = {978-3-319-46597-5}, issn = {0302-9743}, doi = {10.1007/978-3-319-46598-2 7}, url = {http://link.springer.com/chapter/10.1007/978-3-319-46598-2_7}, author = {Ruben Rios and Carmen Fernandez-Gago and Javier Lopez} } @article {nrlSIC16, title = {Testificaci{\'o}n Digital}, journal = {Revista SIC}, volume = {122}, year = {2016}, month = {Nov 2016}, pages = {94-98}, publisher = {Ediciones CODA}, abstract = {

El creciente n{\'u}mero de dispositivos interconectados trae consigo problemas de seguridad bien conocidos; por ejemplo, aquellos debidos a las vulnerabilidades en protocolos muy diversos {\textendash}muchos de ellos propietarios{\textendash} y al factor de error humano introducido por los usuarios. Sin embargo, cabe preguntarse c{\'o}mo podemos usar el despliegue de tales dispositivos en beneficio de la ciberseguridad. En el proyecto IoTest se est{\'a} desarrollando una soluci{\'o}n, el Testigo Digital, que permitir{\'a} a los dispositivos personales con arquitectura de seguridad embebida reaccionar ante ataques virtuales, protegi{\'e}ndonos de los ciberataques emergentes.

}, issn = {1136-0623}, url = {https://revistasic.es/index.php?option=com_content\&view=article\&id=1713\&Itemid=1498}, author = {Ana Nieto and Rodrigo Roman and Javier Lopez} } @inproceedings {1578, title = {Testigo digital: delegaci{\'o}n vinculante de evidencias electr{\'o}nicas para escenarios IoT}, booktitle = {II Jornadas Nacionales de Investigaci{\'o}n en Ciberseguridad (JNIC 2016)}, year = {2016}, month = {06/2016}, pages = {109-116}, abstract = {

En un mundo en el que los usuarios dependen cada vez m{\'a}s de sus dispositivos, {\'e}stos almacenan gran cantidad de datos y son una fuente muy valiosa de informaci{\'o}n sobre su entorno. Sin embargo, la heterogeneidad y la densidad de los objetos conectados, caracter{\'\i}sticas propias de la Internet de las Cosas (IoT), sirven de velo para ocultar conductas maliciosas que afectan a estos dispositivos, sin que quede rastro de tales acciones. En este art{\'\i}culo definimos el concepto de testigo digital: funcionalidad que permitir{\'a} a los dispositivos personales y otros objetos colaborar para implementar una cadena de custodia digital en la IoT. El fin perseguido es ofrecer soluciones que mitiguen los efectos de la ciberdelincuencia, ampar{\'a}ndose en la colaboraci{\'o}n de los dispositivos con arquitecturas de seguridad embebidas para alertar de conductas maliciosas, y dejar constancia de {\'e}stas.

}, keywords = {computaci{\'o}n forense, elemento seguro, Evidencia electr{\'o}nica, IoT, no-repudio}, isbn = {978-84-608-8070-7}, url = {http://ucys.ugr.es/jnic2016/docs/ActasJNIC2016.pdf}, author = {Ana Nieto and Rodrigo Roman and Javier Lopez} } @article {rios2015, title = {Probabilistic receiver-location privacy protection in wireless sensor networks}, journal = {Information Sciences}, volume = {321}, year = {2015}, month = {07/2015}, pages = {205 - 223}, publisher = {Elsevier}, abstract = {

Wireless sensor networks (WSNs) are continually exposed to many types of attacks. Among these, the attacks targeted at the base station are the most devastating ones since this essential device processes and analyses all traffic generated in the network. Moreover, this feature can be exploited by a passive adversary to determine its location based on traffic analysis. This receiver-location privacy problem can be reduced by altering the traffic pattern of the network but the adversary may still be able to reach the base station if he gains access to the routing tables of a number of sensor nodes. In this paper we present HISP-NC (Homogenous Injection for Sink Privacy with Node Compromise protection), a receiver-location privacy solution that consists of two complementary schemes which protect the location of the base station in the presence of traffic analysis and node compromise attacks. The HISP-NC data transmission protocol prevents traffic analysis by probabilistically hiding the flow of real traffic with moderate amounts of fake traffic. Moreover, HISP-NC includes a perturbation mechanism that modifies the routing tables of the nodes to introduce some level of uncertainty in attackers capable of retrieving the routing information from the nodes. Our scheme is validated both analytically and experimentally through extensive simulations.

}, keywords = {node capture, privacy, security, traffic analysis, wireless sensor networks}, issn = {0020-0255}, doi = {10.1016/j.ins.2015.01.016}, author = {Ruben Rios and Jorge Cuellar and Javier Lopez} } @article {NNMSVRLS, title = {Relay Selection for Secure 5G Green Communications}, journal = {Telecommunication Systems }, volume = {59}, year = {2015}, month = {05/2015}, pages = {169-187}, publisher = {Springer US}, abstract = {

In this article, we present relay selection policies in applications with secrecy requirements which are of interest in the fifth generation (5G) of wireless networks. More specifically, we provide a classification of relays based on their distinct communication attributes, such as processing, multiple antennas, storage, channel estimation, density and security level. In addition, we discuss the level of efficiency exhibited by each relay class, regarding their impact in delay-critical applications and green communications applications, while aiming at a specific security level at the physical layer. Then, relay selection policies are proposed taking into consideration the goals set by each application. Numerical evaluation of the proposed policies in terms of the average secrecy rate, average delay and power reduction show improved performance compared to other state-of-the-art solutions.\ 

}, keywords = {5G relays, Delay-critical, Power-efficient communications, Relay selection, security}, issn = {1018-4864}, doi = {10.1007/s11235-014-9890-7}, url = {http://dx.doi.org/10.1007/s11235-014-9890-7}, author = {Nikolaos Nomikos and Ana Nieto and Prodromos Makris and Dimitrios N. Skoutas and Demosthenes Vouyioukas and Panagiotis Rizomiliotis and Javier Lopez and Charalambos Skianis} } @article {PATENTDW15, title = {Testigo digital: procedimientos y dispositivos para la gesti{\'o}n segura de evidencias electr{\'o}nicas con credenciales vinculantes}, journal = {Espa{\~n}a, C. Aut{\'o}n./Reg. de explotaci{\'o}n: Andaluc{\'\i}a}, volume = {P201500764}, year = {2015}, month = {10/2015}, publisher = {G06F 21/00}, type = {Invention Patent}, edition = {Invention Patent}, chapter = {WO2017068222}, address = {Spain}, author = {Ana Nieto and Rodrigo Roman and Javier Lopez} } @inproceedings {onieva2014, title = {An{\'a}lisis y Desarrollo de un Canal Encubierto en una Red de Sensores}, booktitle = { XIII Reuni{\'o}n Espa{\~n}ola sobre Criptolog{\'\i}a y Seguridad de la Informaci{\'o}n (RECSI 2014)}, year = {2014}, month = {09/2014}, pages = {333-338}, publisher = {Universidad de Alicante}, organization = {Universidad de Alicante}, address = {Alicante, Spain}, abstract = {

Continuamente aparecen nuevos estudios as{\'\i} como nuevos desarrollos de canales encubiertos. Como veremos, existen m{\'a}s de cien dise{\~n}os distintos para redes de ordenadores, pero no hemos encontrado en la literatura ning{\'u}n an{\'a}lisis, dise{\~n}o e implementaci{\'o}n de canales encubiertos sobre redes de sensores. En este art{\'\i}culo presentamos los resultados del dise{\~n}o e implementaci{\'o}n de un canal multitasa basado en los tiempos de monitorizaci{\'o}n sobre una red de sensores. En este proceso se han establecido las principales propiedades necesarias y, en base a ellas, se desarrolla e implementa el canal encubierto. Se describe el proceso de desarrollo y se analiza su detectabilidad.

}, keywords = {Covert channels, Information Security, Information Warfare, Intrusion Detection, Network Security, Wireless Sensor Network}, isbn = {978-84-9717-323-0}, author = {Jose A. Onieva and Ruben Rios and Bernardo Palenciano} } @incollection {ruben2014a, title = {Location Privacy in WSNs: Solutions, Challenges, and Future Trends}, booktitle = {Foundations of Security Analysis and Design VII}, volume = {8604}, number = {LNCS}, year = {2014}, pages = {244-282}, publisher = {Springer}, organization = {Springer}, abstract = {

Privacy preservation is gaining popularity in Wireless Sensor Network (WSNs) due to its adoption in everyday scenarios. There are a number of research papers in this area many of which concentrate on the location privacy problem. In this paper we review and categorise these solutions based on the information available to the adversary and his capabilities. But first we analyse whether traditional anonymous communication systems conform to the original requirements of location privacy in sensor networks. Finally, we present and discuss a number of challenges and future trends that demand further attention from the research community.

}, keywords = {Location Privacy, survey, traffic analysis, wireless sensor networks}, isbn = {978-3-319-10081-4}, issn = {0302-9743}, doi = {10.1007/978-3-319-10082-1_9}, author = {Ruben Rios and Javier Lopez and Jorge Cuellar} } @inproceedings {Lopez2014prl, title = {Preserving Receiver-Location Privacy in Wireless Sensor Networks}, booktitle = {Information Security Practice and Experience (ISPEC 2014)}, volume = {8434}, year = {2014}, month = {05/2014}, pages = {15-27}, publisher = {Springer}, organization = {Springer}, address = {Fuzhou, China}, abstract = {

Wireless sensor networks (WSNs) are exposed to many different types of attacks. Among these, the most devastating attack is to compromise or destroy the base station since all communications are addressed exclusively to it. Moreover, this feature can be exploited by a passive adversary to determine the location of this critical device. This receiver-location privacy problem can be reduced by hindering traffic analysis but the adversary may still obtain location information by capturing a subset of sensor nodes in the field. This paper addresses, for the first time, these two problems together in a single solution

}, keywords = {Location Privacy, node capture, traffic analysis, wireless sensor networks}, isbn = {978-3-319-06319-5}, issn = {0302-9743}, doi = {10.1007/978-3-319-06320-1_3}, url = {http://link.springer.com/chapter/10.1007/978-3-319-06320-1_3$\#$}, author = {Javier Lopez and Ruben Rios and Jorge Cuellar} } @inproceedings {moyano14caise, title = {Trust-Aware Decision-Making Methodology for Cloud Sourcing}, booktitle = {26th International Conference on Advanced Information Systems Engineering (CAiSE 2014)}, series = {LCNS}, volume = {8484}, year = {2014}, month = {06/2014}, pages = {136-149}, publisher = {Springer}, organization = {Springer}, address = {Thessaloniki}, abstract = {

Cloud sourcing consists of outsourcing data, services and infrastructure to cloud providers. Even when this outsourcing model brings advantages to cloud customers, new threats also arise as sensitive data and critical IT services are beyond customers{\textquoteright} control. When an organization considers moving to the cloud, IT decision makers must select a cloud provider and must decide which parts of the organization will be outsourced and to which extent. This paper proposes a methodology that allows decision makers to evaluate their trust in cloud providers. The methodology provides a systematic way to elicit knowledge about cloud providers, quantify their trust factors and aggregate them into trust values that can assist the decision-making process. The trust model that we propose is based on trust intervals, which allow capturing uncertainty during the evaluation, and we define an operator for aggregating these trust intervals. The methodology is applied to an eHealth scenario.

}, keywords = {Cloud Computing, decision making, domain knowledge elicitation, security, Trust}, isbn = {978-3-319-07880-9}, issn = {0302-9743}, doi = {10.1007/978-3-319-07881-6}, author = {Francisco Moyano and Kristian Beckers and Carmen Fernandez-Gago}, editor = {Matthias Jarke and John Mylopoulos and Christoph Quix and Colette Rolland and Yannis Manolopoulos and Haralambos Mouratidis and Jennifer Horkoff} } @article {rios2013a, title = {Covert Communications through Network Configuration Messages}, journal = {Computers \& Security}, volume = {39, Part A}, year = {2013}, month = {Nov 2013}, pages = {34 - 46}, publisher = {Elsevier}, abstract = {

Covert channels are a form of hidden communication that may violate the integrity of systems. Since their birth in Multi-Level Security systems in the early 70{\textquoteright}s they have evolved considerably, such that new solutions have appeared for computer networks mainly due to vague protocols specifications. In this paper we concentrate on short-range covert channels and analyze the opportunities of concealing data in various extensively used protocols today. From this analysis we observe several features that can be effectively exploited for subliminal data transmission in the Dynamic Host Configuration Protocol (DHCP). The result is a proof-of-concept implementation, HIDE\_DHCP, which integrates three different covert channels each of which accommodate to different stealthiness and capacity requirements. Finally, we provide a theoretical and experimental analysis of this tool in terms of its reliability, capacity, and detectability.

}, keywords = {Covert channels, Information Warfare, Intrusion Detection, Network Security, System Information Security}, issn = {0167-4048}, doi = {10.1016/j.cose.2013.03.004}, author = {Ruben Rios and Jose A. Onieva and Javier Lopez} } @article {roman2013iot, title = {On the features and challenges of security and privacy in distributed internet of things}, journal = {Computer Networks}, volume = {57}, year = {2013}, month = {July 2013}, pages = {2266{\textendash}2279}, publisher = {Elsevier}, abstract = {

In the Internet of Things, services can be provisioned using centralized architectures, where central entities acquire, process, and provide information. Alternatively, distributed architectures, where entities at the edge of the network exchange information and collaborate with each other in a dynamic way, can also be used. In order to understand the applicability and viability of this distributed approach, it is necessary to know its advantages and disadvantages {\textendash} not only in terms of features but also in terms of security and privacy challenges. The purpose of this paper is to show that the distributed approach has various challenges that need to be solved, but also various interesting properties and strengths.

}, keywords = {Internet of Things, Wireless Sensor Network}, issn = {1389-1286}, doi = {10.1016/j.comnet.2012.12.018}, url = {http://www.sciencedirect.com/science/article/pii/S1389128613000054}, author = {Rodrigo Roman and Jianying Zhou and Javier Lopez} } @inproceedings {rios2013b, title = {Ocultaci{\'o}n de la estaci{\'o}n base en redes inal{\'a}mbricas de sensores}, booktitle = {XI Jornadas de Ingenier{\'\i}a Telem{\'a}tica (JITEL 2013)}, year = {2013}, month = {Oct 2013}, pages = {481-486}, publisher = {Asociaci{\'o}n de Telem{\'a}tica}, organization = {Asociaci{\'o}n de Telem{\'a}tica}, address = {Granada}, abstract = {

La estaci{\'o}n base es el elemento m{\'a}s importante en un red de sensores y, por tanto, es necesario evitar que un atacante pueda hacerse con el control de este valioso dispositivo. Para ello, el atacante puede valerse tanto de t{\'e}cnicas de an{\'a}lisis de tr{\'a}fico como de la captura de nodos. En este trabajo presentamos un esquema que consta de dos fases, la primera est{\'a} dedicada a homogeneizar los patrones de tr{\'a}fico y la segunda encargada de perturbar las tablas de rutas de los nodos. Ambas fases permiten mantener a la estaci{\'o}n base fuera del alcance del atacante con un coste computacional insignificante y un consumo energ{\'e}tico moderado. La validez de nuestro esquema ha sido validada anal{\'\i}ticamente y a trav{\'e}s de numerosas simulaciones.

}, isbn = {978-84-616-5597-7}, author = {Ruben Rios and Jorge Cuellar and Javier Lopez}, editor = {Jes{\'u}s E. D{\'\i}az Verdejo and Jorge Navarro Ortiz and Juan J. Ramos Mu{\~n}oz} } @article {agudo2013, title = {A Privacy-Aware Continuous Authentication Scheme for Proximity-Based Access Control}, journal = {Computers \& Security}, volume = {39 (B)}, year = {2013}, month = {11/2013}, pages = {117-126}, publisher = {Elsevier}, abstract = {

Continuous authentication is mainly associated with the use of biometrics to guarantee that a resource is being accessed by the same user throughout the usage period. Wireless devices can also serve as a supporting technology for continuous authentication or even as a complete alternative to biometrics when accessing proximity-based services. In this paper we present the implementation of a secure, non-invasive continuous authentication scheme supported by the use of Wearable Wireless Devices (WWD), which allow users to gain access to proximity-based services while preserving their privacy. Additionally we devise an improved scheme that circumvents some of the limitations of our implementation.

}, issn = {0167-4048}, doi = {10.1016/j.cose.2013.05.004}, author = {Isaac Agudo and Ruben Rios and Javier Lopez} } @article {1752, title = {Security of Industrial Sensor Network-based Remote Substations in the context of the Internet of Things}, journal = {Ad Hoc Networks}, volume = {11}, year = {2013}, month = {2013}, pages = {1091{\textendash}1104}, publisher = {Elsevier}, abstract = {

The main objective of remote substations is to provide the central system with sensitive information from critical infrastructures, such as generation, distribution or transmission power systems. Wireless sensor networks have been recently applied in this particular context due to their attractive services and inherent benefits, such as simplicity, reliability and cost savings. However, as the number of control and data acquisition systems that use the Internet infrastructure to connect to substations increases, it is necessary to consider what connectivity model the sensor infrastructure should follow: either completely isolated from the Internet or integrated with it as part of the Internet of Things paradigm. This paper therefore addresses this question by providing a thorough analysis of both security requirements and infrastructural requirements corresponding to all those TCP/IP integration strategies that can be applicable to networks with constrained computational resources.

}, keywords = {Industrial Control Networks, Internet of Things, Supervisory Control and Data Acquisition (SCADA) Systems, The Internet, wireless sensor networks}, issn = {1570-8705}, doi = {http://dx.doi.org/10.1016/j.adhoc.2012.12.001}, author = {Cristina Alcaraz and Rodrigo Roman and Pablo Najera and Javier Lopez} } @article {1770, title = {Smart Control of Operational Threats in Control Substations}, journal = {Computers \& Security}, volume = {38}, year = {2013}, month = {OCT 2013}, pages = {14-27}, publisher = {Elsevier}, abstract = {

Any deliberate or unsuitable operational action in control tasks of critical infrastructures, such as energy generation, transmission and distribution systems that comprise sub-domains of a Smart Grid, could have a significant impact on the digital economy: without energy, the digital economy cannot live. In addition, the vast majority of these types of critical systems are configured in isolated locations where their control depends on the ability of a few, supposedly trustworthy, human operators. However, this assumption of reliabilty is not always true. Malicious human operators (criminal insiders) might take advantage of these situations to intentionally manipulate the critical nature of the underlying infrastructure. These criminal actions could be not attending to emergency events, inadequately responding to incidents or trying to alter the normal behaviour of the system with malicious actions. For this reason, in\ this paper we propose a smart response mechanism that controls human operators{\textquoteright} operational threats at all times. Moreover, the design of this mechanism allows the system to be able to not only evaluate by itself, the situation of a particular scenario but also to take control when areas are totally unprotected and/or isolated. The response mechanism, which is based on Industrial Wireless Sensor Networks (IWSNs) for the constant monitoring of observed critical\ infrastructures, on reputation for controlling human operators{\textquoteright} actions, and on the ISA100.11a standard for alarm management, has been implemented and simulated to evaluate its feasibility for critical contexts.

}, keywords = {Digital Economy, Energy Control Systems, Reputation, security, Smart grids, wireless sensor networks}, issn = {0167-4048}, doi = {https://doi.org/10.1016/j.cose.2013.03.013}, url = {http://www.sciencedirect.com/science/article/pii/S0167404813000588}, author = {Javier Lopez and Cristina Alcaraz and Rodrigo Roman} } @article {Rios2012a, title = {(Un)Suitability of Anonymous Communication Systems to WSN}, journal = {IEEE Systems Journal}, volume = {7}, number = {2}, year = {2013}, month = {Jun 2013}, pages = {298 - 310}, publisher = {IEEE Systems Council}, abstract = {

Anonymous communication systems have been extensively studied by the research community to prevent the disclosure of sensitive information from the analysis of individuals{\textquoteright} traffic patterns. Many remarkable solutions have been developed in this area, most of which have proven to be effective in the protection of user privacy against different types of attacks. Recently, the privacy preservation problem has also been considered in the realm of wireless sensor networks (WSNs) due to their imminent adoption in real-world scenarios. A special challenge that arises from the analysis of the flow of sensor nodes{\textquoteright} communications is the location privacy problem. In this work we concentrate on analyzing the suitability of traditional anonymous communication systems originally designed for the Internet to the original scenario of sensor networks. The results show that, in most cases, traditional solutions do not provide the adequate protection means for the particular problem of location privacy, while other solutions are too resource-consuming for the restricted capabilities of sensor nodes.

}, keywords = {Anonymous communication, Location Privacy, wireless sensor networks}, issn = {1932-8184}, doi = {10.1109/JSYST.2012.2221956}, author = {Ruben Rios and Javier Lopez} } @article {najerascn12, title = {User-centric secure integration of personal RFID tags and sensor networks}, journal = {Security and Communication Networks}, volume = {6}, year = {2013}, month = {Oct 2013}, pages = {1177{\textendash}1197}, publisher = {Wiley-Blackwell}, abstract = {

A personal network (PN) should enable the collaboration of user{\textquoteright}s devices and services in a flexible, self-organizing and friendly manner. For such purpose, the PN must securely accommodate heterogeneous technologies with uneven computational and communication resources. In particular, personal RFID tags can enable seamless recognition of user{\textquoteright}s context, provide user authentication and enable novel services enhancing the quality and quantity of data handled by the PN. However, the highly constrained features of common RFID tags and their passive role in the network highlights the need of an adequate secure communication model with personal tags which enables their participation as a member of the PN. In this paper, we present our concept of PN, with special emphasis on the role of RFID and sensor networks, and define a secure architecture for PNs including methods for the secure access to context-aware technologies from both local PN members and the Internet of Things. The PN architecture is designed to support differentiated security mechanisms to maximize the level of security for each type of personal device. Furthermore, we analyze which security solutions available in the literature can be adapted for our architecture, as well as the challenges and security mechanisms still necessary in the secure integration of personal tags.

}, issn = {1939-0114}, doi = {10.1002/sec.684}, url = {http://dx.doi.org/10.1002/sec.684}, author = {Pablo Najera and Rodrigo Roman and Javier Lopez} } @inproceedings {Rios2012b, title = {Adecuaci{\'o}n de soluciones de anonimato al problema de la privacidad de localizaci{\'o}n en WSN}, booktitle = {XII Reuni{\'o}n Espa{\~n}ola sobre Criptolog{\'\i}a y Seguridad de la Informaci{\'o}n (RECSI 2012)}, year = {2012}, month = {Sep 2012}, pages = {309-314}, address = {Donostia-San Sebasti{\'a}n}, abstract = {

Los patrones de tr{\'a}fico caracter{\'\i}sticos de las redes inal{\'a}mbricas de sensores (WSNs) dan lugar al problema de la privacidad de localizaci{\'o}n. De manera similar, el tr{\'a}fico de los usuarios en Internet revela informaci{\'o}n sensible que puede ser protegida mediante sistemas de comunicaci{\'o}n an{\'o}nima (ACS). Por ello, este trabajo analiza la posibilidad de adaptar las soluciones de anonimato tradicionales al problema particular de las redes de sensores. Hasta el momento estas soluciones hab{\'\i}an sido rechazadas sin un an{\'a}lisis riguroso, argumentando simplemente que eran demasiado exigentes computacionalmente para los nodos sensores. Nuestros resultados demuestran que, en general, algunos ACS no cumplen los requisitos de privacidad necesarios en WSNs mientras que otros, que si los cumplen, se valen de una cantidad de recursos que superan la capacidad de los sensores.

}, isbn = {978-84-615-9933-2}, author = {Ruben Rios and Javier Lopez}, editor = {U. Zurutuza and R. Uribeetxeberria and I. Arenaza-Nu{\~n}o} } @article {Roman2010a, title = {Advanced Secure Multimedia Services for Digital Homes}, journal = {Information Systems Frontiers}, volume = {14}, year = {2012}, month = {July 2012}, pages = {527-540}, publisher = {Springer}, abstract = {

Our society is becoming increasingly more IT-oriented, and the images and sounds that reflect our daily life are being stored mainly in a digital form. This digital personal life can be part of the home multimedia contents, and users demand access and possibly share these contents (such as photographs, videos, and music) in an ubiquitous way: from any location and with any device. The purpose of this article is twofold. First, we introduce the Feel@Home system, whose main objective is to enable the previously mentioned vision of an ubiquitous digital personal life. Second, we describe the security architecture of Feel@Home, analyzing the security and privacy requirements that identify which threats and vulnerabilities must be considered, and deriving the security building blocks that can be used to protect both IMS-based and VPN-based solutions.

}, keywords = {Content sharing, Digital home, Multimedia, privacy, security}, issn = {1387-3326}, doi = {10.1007/s10796-010-9258-9}, url = {http://www.springerlink.com/content/1785645v5246006u/}, author = {Rodrigo Roman and Javier Lopez and Olivier Dugeon and Marc Lacoste and Pierre Plaza Tron and Marta Bel} } @article {Galindo2010, title = {On the Energy Cost of Authenticated Key Agreement in Wireless Sensor Networks}, journal = {Wireless Communications and Mobile Computing}, volume = {12}, year = {2012}, month = {Jan 2012}, pages = {133-143}, publisher = {Wiley}, abstract = {

Wireless sensors are battery-powered devices which are highly constrained in terms of computational capabilities, memory and communication bandwidth. While battery life is their main limitation, they require considerable energy to communicate data. Due to this, it turns out that the energy saving of computationally inexpensive primitives (like symmetric key cryptography (SKC)) can be nullified by the bigger amount of data they require to be sent. In this work, we study the energy cost of key agreement protocols between peers in a network using asymmetric key cryptography. Our main concern is to reduce the amount of data to be exchanged, which can be done by using special cryptographic paradigms like identity-based and self-certified cryptography. The main news is that an intensive computational primitive for resource-constrained devices, such as non-interactive identity-based authenticated key exchange, performs comparably or even better than traditional authenticated key exchange (AKE) in a variety of scenarios. Moreover, protocols based in this primitive can provide better security properties in real deployments than other simple protocols based on symmetric cryptography. Our findings illustrate to what extent the latest implementation advancements push the efficiency boundaries of public key cryptography (PKC) in wireless sensor networks (WSNs).

}, keywords = {identity-based key agreement, key distribution, pairings, underwater wireless sensor networks, wireless sensor networks}, issn = {1530-8669}, doi = {10.1002/wcm.894}, url = {http://dx.doi.org/10.1002/wcm.894}, author = {David Galindo and Rodrigo Roman and Javier Lopez} } @inproceedings {Rios2012, title = {HIDE_DHCP: Covert Communications Through Network Configuration Messages}, booktitle = {Proceedings of the 27th IFIP TC 11 International Information Security and Privacy Conference (SEC 2012)}, series = {IFIP AICT}, volume = {376}, year = {2012}, month = {June 2012}, pages = {162-173}, publisher = {Springer Boston}, organization = {Springer Boston}, address = {Heraklion, Crete, Greece}, abstract = {

Covert channels are a form of hidden communication that may violate the integrity of systems. Since their birth in multilevel security systems in the early 70{\textquoteright}s they have evolved considerably, such that new solutions have appeared for computer networks mainly due to vague protocols specifications. We analyze a protocol extensively used today, the Dynamic Host Configuration Protocol (DHCP), in search of new forms of covert communication. From this analysis we observe several features that can be effectively exploited for subliminal data transmission. This results in the implementation of HIDE_DHCP, which integrates three covert channels that accommodate to different stealthiness and bandwidth requirements

}, keywords = {Covert channels, Network Security, System Information Security}, isbn = {978-3-642-30435-4}, issn = {1868-4238}, doi = {http://dx.doi.org/10.1007/978-3-642-30436-1_14}, author = {Ruben Rios and Jose A. Onieva and Javier Lopez}, editor = {Dimitris Gritzalis and Steve Furnell and Marianthi Theoharidou} } @inproceedings {Cuellar2012, title = {Indistinguishable Regions in Geographic Privacy}, booktitle = {Proceedings of the 27th Annual ACM Symposium on Applied Computing (SAC 2012)}, year = {2012}, month = {26-30 March 2012}, pages = {1463-1469}, publisher = {ACM}, organization = {ACM}, address = {Riva del Garda (Trento), Italy}, abstract = {

The ubiquity of positioning devices poses a natural security challenge: users want to take advantage of location-related services as well as social sharing of their position but at the same time have security concerns about how much information should be shared about their exact position. This paper discusses different location-privacy problems, their formalization and the novel notion of indistinguishability regions that allows one to proof that a given obfuscation function provides a good trade-off between location sharing and privacy.

}, keywords = {indistinguishability, Location Privacy, obfuscation}, isbn = {978-1-4503-0857-1}, doi = {10.1145/2245276.2232010}, author = {Jorge Cuellar and Martin Ochoa and Ruben Rios}, editor = {Sascha Ossowski and Paola Lecca} } @inproceedings {Rios2012d, title = {Robust Probabilistic Fake Packet Injection for Receiver-Location Privacy in WSN}, booktitle = {17th European Symposium on Research in Computer Security (ESORICS 2012)}, series = {LNCS}, volume = {7459}, year = {2012}, month = {Sep 2012}, pages = {163-180}, publisher = {Springer}, organization = {Springer}, address = {Pisa, Italy}, abstract = {

The singular communication model in wireless sensor networks (WSNs) originate pronounced traffic patterns that allow a local observer to deduce the location of the base station, which must be kept secret for both strategical and security reasons. In this work we present a new receiver-location privacy solution called HISP (Homogenous Injection for Sink Privacy). Our scheme is based on the idea of hiding the flow of real traffic by carefully injecting fake traffic to homogenize the transmissions from a node to its neighbors. This process is guided by a lightweight probabilistic approach ensuring that the adversary cannot decide with sufficient precision in which direction to move while maintaining a moderate amount of fake traffic. Our system is both validated analytically and experimentally through simulations.

}, isbn = {978-3-642-33167-1}, issn = {0302-9743}, doi = {10.1007/978-3-642-33167-1_10}, author = {Ruben Rios and Jorge Cuellar and Javier Lopez}, editor = {Sara Foresti and Moti Yung and Fabio Martinelli} } @inproceedings {Najera_STM11, title = {Secure architecure for the integration of RFID and sensors in personal networks}, booktitle = {7th International Workshop on Security and Trust Management (STM{\textquoteright}11)}, series = {LNCS}, volume = {7170}, year = {2012}, pages = {207-222}, publisher = {Springer}, organization = {Springer}, address = {Copenhagen, Denmark}, abstract = {

The secure integration of RFID technology into the personal network paradigm, as a context-aware technology which complements body sensor networks, would provide notable benefits to applications and potential services of the PN. RFID security as an independent technology is reaching an adequate maturity level thanks to research in recent years; however, its integration into the PN model, interaction with other network resources, remote users and service providers requires a specific security analysis and a PN architecture prepared to support these resource-constrained pervasive technologies. This paper provides such PN architecture and analysis. Aspects such as the management of personal tags as members of the PN, the authentication and secure communication of PN nodes and remote users with the context-aware technologies, and the enforcement of security and privacy policies are discussed in the architecture.

}, isbn = {978-3-642-29962-9}, doi = {10.1007/978-3-642-29963-6_15}, author = {Pablo Najera and Rodrigo Roman and Javier Lopez} } @article {AlcarazR2012, title = {Selecting key management schemes for WSN applications}, journal = {Computers \& Security}, volume = {31}, number = {38}, year = {2012}, month = {Nov 2012}, pages = {956{\textendash}966}, publisher = {Elsevier}, abstract = {

Key management in wireless sensor networks (WSN) is an active research topic. Due to the fact that a large number of key management schemes (KMS) have been proposed in the literature, it is not easy for a sensor network designer to know exactly which KMS best fits in a particular WSN application. In this article, we offer a comprehensive review on how the application requirements and the properties of various key management schemes influence each other. Based on this review, we show that the KMS plays a critical role in determining the security performance of a WSN network with given application requirements. We also develop a method that allows the network designers to select the most suitable KMS for a specific WSN network setting. In addition, the article also addresses the issues on the current state-of-the-art research on the KMS for homogeneous (i.e. non-hierarchical) networks to provide solutions for establishing link-layer keys in various WSN applications and scenarios.

}, keywords = {security}, issn = {0167-4048}, doi = {10.1016/j.cose.2012.07.002}, url = {http://www.sciencedirect.com/science/article/pii/S0167404812001034}, author = {Cristina Alcaraz and Javier Lopez and Rodrigo Roman and Hsiao-Hwa Chen} } @inproceedings {neumann2012strong, title = {Strong Authentication of Humans and Machines in Policy Controlled Cloud Computing Environment Using Automatic Cyber Identity}, booktitle = {Information Security Solutions Europe 2012}, year = {2012}, month = {2012}, pages = {195-206}, publisher = {Springer Vieweg}, organization = {Springer Vieweg}, address = {Brussels, Belgium}, abstract = {

The paper describes the experience with integration of automatic cyber identity technology with policy controlled virtualisation environment. One identity technology has been used to enable strong authentication of users (human beings) as well as machines (host systems) to the virtualization management system. The real experimental evaluation has been done in PASSIVE project (Policy-Assessed system-level Security of Sensitive Information processing in Virtualised Environments - SEVENTH FRAMEWORK PROGRAMME THEME ICT-2009.1.4 INFORMATION AND COMMUNICATION TECHNOLOGIES - Small or medium-scale focused research project - Grant agreement no.: 257644).

}, isbn = {978-3-658-00332-6}, doi = {10.1007/978-3-658-00333-3_19}, author = {Neumann Libor and Tomas Halman and Rotek Pavel and Alexander Boettcher and Julian Stecklina and Michal Sojka and David Nu{\~n}ez and Isaac Agudo}, editor = {Norbert Pohlmann and Helmut Reimer and Wolfgang Schneider} } @inproceedings {Clarke:2012, title = {Trust \& Security RTD in the Internet of Things: Opportunities for International Cooperation}, booktitle = {Proceedings of the First International Conference on Security of Internet of Things}, series = {SecurIT {\textquoteright}12}, year = {2012}, pages = {172{\textendash}178}, publisher = {ACM}, organization = {ACM}, address = {New York, NY, USA}, abstract = {

While there has been considerable progress in the research and technological development (RTD) of the Internet of Things (IoT), there is still considerable RTD required by international communities for the trust, privacy and security research challenges arising from the constitution of the IoT architectures, infrastructures, communications, devices, objects, applications and services. In this paper, we present an thorough analysis of the ongoing and future RTD work, specifically in Europe, regarding trust, privacy and security of the Internet of Things with a view towards enabling international cooperation efforts around the globe to solve these major research challenges.

}, keywords = {international cooperation (INCO), Internet of Things, privacy, research and technological development (RTD), security, Trust}, isbn = {978-1-4503-1822-8}, doi = {10.1145/2490428.2490452}, url = {http://doi.acm.org/10.1145/2490428.2490452}, author = {Clarke, James and Roman, Rodrigo and Sharma, Abhishek and Lopez, Javier and Suri, Neeraj} } @inproceedings {Najera_JITEL11, title = {Acceso seguro a nodos RFID en una arquitectura de red personal}, booktitle = {X Jornadas de Ingenier{\'\i}a Telem{\'a}tica (JITEL 2011)}, year = {2011}, month = {09/2011}, pages = {104 - 111}, publisher = {Universidad de Cantabria}, organization = {Universidad de Cantabria}, address = {Santander, Spain}, abstract = {

El paradigma de red personal (PN) permitir\á la interacci\ón y colaboraci\ón del creciente abanico de dispositivos personales. Con tal fin la PN ha de integrar en su seno m\últiples tecnolog\ías heterog\éneas con diversas capacidades computacionales y de comunicaci\ón de forma segura. En particular, la incorporaci\ón de la tecnolog\ía RFID en objetos personales conlleva m\últiples riesgos de seguridad y privacidad que han suscitado un elevado inter\és de la comunidad investigadora en los \últimos a\ños. M\ás all\á de su seguridad de forma aislada, su integraci\ón en la PN y la interacci\ón de \ésta con redes de \área extensa como Internet of Things requieren una arquitectura de red personal adecuada para tal contexto. Este art\ículo proporciona los fundamentos de tal arquitectura segura incluyendo el an\álisis de aspectos como la incorporaci\ón e inicializaci\ón de las restringidas etiquetas RFID en la red personal, la autenticaci\ón tanto de miembros de la PN como de usuarios y servicios remotos en su acceso a las tecnolog\ías de contexto, el control de las pol\íticas de privacidad y el establecimiento de canales seguros de comunicaci\ón supervisados.

}, keywords = {arquitectura software, red personal, Seguridad RFID}, isbn = {978-84-694-5948-5}, author = {Pablo Najera and Rodrigo Roman and Javier Lopez}, editor = {Klaus Hackbarth and Ram{\'o}n Ag{\"u}ero and Roberto Sanz} } @article {Rios2011a, title = {Analysis of Location Privacy Solutions in Wireless Sensor Networks}, journal = {IET Communications}, volume = {5}, year = {2011}, month = {Nov 2011}, pages = {2518 - 2532}, publisher = {Institution of Engineering and Technology}, abstract = {

Extensive work has been done on the protection of Wireless Sensor Networks (WSNs) from the hardware to the application layer. However, only recently, the privacy preservation problem has drawn the attention of the research community because of its challenging nature. This problem is exacerbated in the domain of WSNs due to the extreme resource limitation of sensor nodes. In this paper we focus on the location privacy problem in WSNs, which allows an adversary to determine the location of nodes of interest to him. We provide a taxonomy of solutions based on the power of the adversary and the main techniques proposed by the various solutions. In addition, we describe and analyse the advantages and disadvantages of different approaches. Finally, we discuss some open challenges and future directions of research.

}, issn = {1751-8628}, doi = {10.1049/iet-com.2010.0825}, author = {Ruben Rios and Javier Lopez} } @inproceedings {1642, title = {Analysis of Secure Mobile Grid Systems: A systematic approach}, booktitle = {XVI Jornadas de Ingenier{\'\i}a del Software y Bases de Datos (JISBD 2011)}, year = {2011}, month = {2011}, pages = {487-491}, publisher = {Servizo de publicaci{\'o}ns da Universidade da Coru{\~n}a}, organization = {Servizo de publicaci{\'o}ns da Universidade da Coru{\~n}a}, address = {A Coru{\~n}a, Spain}, abstract = {

Developing software through systematic processes is becoming more and more important due to the growing complexity of software development. It is important that the development process used integrates security aspects from the first stages at the same level as other functional and non-functional requirements. The identification of security aspects in the first stages ensures a more robust development and permits the security requirements to be perfectly coupled with the design and the rest of the system\’s requirements. Systems which are based on Grid Computing are a kind of systems that have clear differentiating features in which security is a highly important aspect. Generic development processes are sometimes used to develop Grid specific systems without taking into consideration either the subjacent technological environment or the special features and particularities of these specific systems. In fact, the majority of existing Grid applications have been built without a systematic development process and are based on ad hoc developments.

}, isbn = {978-84-9749-486-1}, author = {David G. Rosado and E. Fernandez-Medina and M. Pattini and Javier Lopez} } @article {Roman2010, title = {A Cross-layer Approach for Integrating Security Mechanisms in Sensor Networks Architectures}, journal = {Wireless Communications and Mobile Computing}, volume = {11}, year = {2011}, pages = {267-276}, publisher = {Wiley}, abstract = {

The wireless sensor networks (WSN) paradigm is especially vulnerable against external and internal attacks. Therefore, it is necessary to develop security mechanisms and protocols to protect them. These mechanisms must become an integral part of the software architecture and network stack of a sensor node. A question that remains is how to achieve this integration. In this paper we check how both academic and industrial solutions tackle this issue, and we present the concept of a transversal layer, where all the different security mechanisms could be contained. This way, all the elements of the architecture can interact with the security mechanisms, and the security mechanisms can have a holistic point of view of the whole architecture. We discuss the advantages of this approach, and also present how the transversal layer concept was applied to a real middleware architecture.

}, keywords = {architecture, cross-layer, middleware, security, Sensor Networks}, issn = {1530-8669}, doi = {10.1002/wcm.1006}, url = {http://dx.doi.org/10.1002/wcm.1006}, author = {Rodrigo Roman and Javier Lopez and Pablo Najera} } @inproceedings {agudo2011cryptography, title = {Cryptography Goes to the Cloud}, booktitle = {1st International Workshop on Security and Trust for Applications in Virtualised Environments (STAVE 2011)}, series = {Communications in Computer and Information Science}, volume = {187}, year = {2011}, month = {June}, pages = {190-197}, publisher = {Springer}, organization = {Springer}, abstract = {

In this paper we identify some areas where cryptography can help a rapid adoption of cloud computing. Although secure storage has already captured the attention of many cloud providers, offering a higher level of protection for their customer{\textquoteright}s data, we think that more advanced techniques such as searchable encryption and secure outsourced computation will become popular in the near future, opening the doors of the Cloud to customers with higher security requirements.

}, isbn = {978-3-642-22364-8}, doi = {10.1007/978-3-642-22365-5_23}, author = {Isaac Agudo and David Nu{\~n}ez and Gabriele Giammatteo and Panagiotis Rizomiliotis and Costas Lambrinoudakis}, editor = {Changhoon Lee and Jean-Marc Seigneur and James J. Park and Roland R. Wagner} } @book {RomFatH11, title = {Digital Home Networking}, year = {2011}, publisher = {Wiley-ISTE}, organization = {Wiley-ISTE}, issn = {1848213212}, url = {http://as.wiley.com/WileyCDA/WileyTitle/productCd-1848213212.html}, author = {Romain Carbou and Michel Diaz and Ernesto Exposito and Rodrigo Roman} } @incollection {Alcaraz2011_ChapterBook, title = {Digital Home Networking: Standards}, booktitle = {Digital Home Networking}, number = {7130}, year = {2011}, pages = {60-96}, publisher = {John Wiley \& Sons Inc.}, organization = {John Wiley \& Sons Inc.}, address = {Reino Unido}, keywords = {Standards, ZigBee}, issn = {978-1-84821-321-0}, author = {Remi Bars and Jorge Gomez and Mohamed Mahdi and Cristina Alcaraz and Rodrigo Roman}, editor = {Romain Carbou and Ernesto Exposito and Rodrigo Roman and Michel Diaz} } @article {Rios2011b, title = {Exploiting Context-Awareness to Enhance Source-Location Privacy in Wireless Sensor Networks}, journal = {The Computer Journal}, volume = {54}, year = {2011}, month = {Sept 2011}, pages = {1603-1615}, publisher = {Oxford University Press}, abstract = {

The source-location privacy problem in Wireless Sensor Networks has been traditionally tackled by the creation of random routes for every packet transmitted from the source nodes to the base station. These schemes provide a considerable protection level at a high cost in terms of message delivery time and energy consumption. This overhead is due to the fact that the data routing process is done in a blind way, without knowledge about the location of the attacker. In this work we propose the Context-Aware Location Privacy (CALP) approach, which takes advantage of the ability of sensor nodes to perceive the presence of a mobile adversary in their vicinity in order to transmit data packets in a more energy-efficient and privacy-preserving manner. In particular, we apply the concepts of CALP to the development of a shortest-path CALP routing algorithm. A permissive and a strict version of the protocol are studied for different adversarial models and the proposed schemes are evaluated through simulation experiments in terms of privacy protection and energy consumption. Finally, we present the conclusions of the paper as well as possible extensions of this work.

}, keywords = {Context-Awareness, Location Privacy, wireless sensor networks}, issn = {0010-4620}, doi = {10.1093/comjnl/bxr055}, author = {Ruben Rios and Javier Lopez} } @article {roman2011, title = {Key management systems for sensor networks in the context of the Internet of Things}, journal = {Computers \& Electrical Engineering}, volume = {37}, year = {2011}, month = {Mar 2011}, pages = {147-159}, publisher = {Elsevier}, abstract = {

If a wireless sensor network (WSN) is to be completely integrated into the Internet as part of the Internet of Things (IoT), it is necessary to consider various security challenges, such as the creation of a secure channel between an Internet host and a sensor node. In order to create such a channel, it is necessary to provide key management mechanisms that allow two remote devices to negotiate certain security credentials (e.g. secret keys) that will be used to protect the information flow. In this paper we will analyse not only the applicability of existing mechanisms such as public key cryptography and pre-shared keys for sensor nodes in the IoT context, but also the applicability of those link-layer oriented key management systems (KMS) whose original purpose is to provide shared keys for sensor nodes belonging to the same WSN.

}, issn = {0045-7906}, doi = {10.1016/j.compeleceng.2011.01.009}, url = {http://www.sciencedirect.com/science/article/B6V25-527FRSD-1/2/62661c595153993639c43b9b331d8d66}, author = {Rodrigo Roman and Cristina Alcaraz and Javier Lopez and Nicolas Sklavos} } @incollection {Najera_DHNChapter, title = {Network Technologies}, booktitle = {Digital Home Networking}, year = {2011}, pages = {17 - 58}, publisher = {Wiley-ISTE}, organization = {Wiley-ISTE}, isbn = {978-1848213210}, author = {Pablo Najera and Ana Nieto}, editor = {Romain Carbou and Ernesto Exposito and Rodrigo Roman} } @article {Alcaraz2011a, title = {Secure SCADA Framework for the Protection of Energy Control Systems}, journal = {Concurrency and Computation Practice \& Experience}, volume = {23}, number = {12}, year = {2011}, month = {Aug 2011}, pages = {1414-1430}, publisher = {John Wiley \& Sons, Inc.}, abstract = {

Energy distribution systems are becoming increasingly widespread in today{\textquoteright}s society.\ One of the elements that is used to monitor and control these systems are the SCADA\ (Supervisory Control and Data Acquisition) systems. In particular, these control systems\ and their complexities, together with the emerging use of the Internet and wireless\ technologies, bring new challenges that must be carefully considered. Examples of such\ challenges are the particular bene{\textasciimacron}ts of the integration of those new technologies, and\ also the e{\textregistered}ects they may have on the overall SCADA security. The main task of this\ paper is to provide a framework that shows how the integration of di{\textregistered}erent state-of-the-art technologies in an energy control system, such as Wireless Sensor Networks (WSNs),\ Mobile Ad-Hoc Networks (MANETs), and the Internet, can bring some interesting\ benefits such as status management and anomaly prevention, while maintaining the\ security of the whole system.

}, keywords = {Energy Distribution and Control Systems, SCADA Systems, Sensor Networks}, isbn = {23(12)1311-1464 (2011)}, issn = {1532-0626}, doi = {10.1002/cpe.1679}, author = {Cristina Alcaraz and Javier Lopez and Jianying Zhou and Rodrigo Roman} } @article {1633, title = {Securing the Internet of Things}, journal = {IEEE Computer}, volume = {44}, number = {9}, year = {2011}, month = {Sept 2011}, pages = {51 -58}, publisher = {IEEE}, abstract = {

This paper presents security of Internet of things. In the Internet of Things vision, every physical object has a virtual component that can produce and consume services Such extreme interconnection will bring unprecedented convenience and economy, but it will also require novel approaches to ensure its safe and ethical use. The Internet and its users are already under continual attack, and a growing economy-replete with business models that undermine the Internet{\textquoteright}s ethical use-is fully focused on exploiting the current version{\textquoteright}s foundational weaknesses.

}, keywords = {business models, computer network security, Internet, Internet of Things, Internet security, IoT, virtual component}, issn = {0018-9162}, doi = {10.1109/MC.2011.291}, url = {http://dx.doi.org/10.1109/MC.2011.291}, author = {Rodrigo Roman and Pablo Najera and Javier Lopez} } @incollection {Moyano_DHNChapter, title = {Security}, booktitle = {Digital Home Networking}, year = {2011}, pages = {139-202}, chapter = {Security}, issn = {9781848213210}, author = {Francisco Moyano and Rodrigo Roman and Anas Abou El Kalam and Marc Lacoste and Mohamed Maachaoui}, editor = {Romain Carbou and Michel Diaz and Ernesto Exposito and Rodrigo Roman} } @incollection {1626, title = {Security in the Developments Process of Mobile Grid Systems}, booktitle = {Advances in Grid Computing}, year = {2011}, pages = {173-198}, publisher = {Intech}, organization = {Intech}, edition = {Zoran Constantinescu}, author = {David G. Rosado and E. Fernandez-Medina and Javier Lopez} } @article {rosado2010d, title = {Security Services Architecture for Secure Mobile Grid Systems}, journal = {Journal of Systems Architecture}, volume = {57}, year = {2011}, month = {2011}, pages = {240-258}, publisher = {Elsevier}, address = {Mobile Grid, is a full inheritor of the Grid with the additional feature that it supports mobile users and resources. Security is an important aspect in Grid based systems, and it is more complex to ensure this in a mobile platform owing to the limitation}, abstract = {

\ Mobile Grid, is a full inheritor of the Grid with the additional feature that it supports mobile users andresources. Security is an important aspect in Grid based systems, and it is more complex to ensure thisin a mobile platform owing to the limitations of resources in these devices. A Grid infrastructure that supportsthe participation of mobile nodes and incorporates security aspects will thus play a significant rolein the development of Grid computing. The idea of developing software through systematic developmentprocesses to improve software quality is not new. However, many information systems such as those ofGrid Computing are still not developed through methodologies which have been adapted to their mostdifferentiating features. The lack of adequate development methods for this kind of systems in whichsecurity is taken into account has encouraged us to build a methodology to develop them, offering adetailed guide for their analysis, design and implementation. It is important to use software V\&V techniques,according to IEEE Std. 1012 for Software Verification and Validation, to ensure that a software systemmeets the operational needs of the user. This ensures that the requirements for the system arecorrect, complete, and consistent, and that the life-cycle products correctly design and implement systemrequirements. This paper shows part of a development process that we are elaborating for the constructionof information systems based on Grid Computing, which are highly dependent on mobile devices inwhich security plays a highly important role. In the design activity of the process, we design a securityarchitecture which serves as a reference for any mobile Grid application that we wish to build since thissecurity architecture defines a complete set of security services which will be instantiated depending onthe requirements and features found in previous activities of the process. A V\&V task is also defined in thedesign activity to validate and verify both the architecture built and the traceability of the artifacts generatedin this activity. In this paper, we will present the service-oriented security architecture for MobileGrid Systems which considers all possible security services that may be required for any mobile Grid application.

}, issn = {1383-7621}, author = {David G. Rosado and Eduardo Fernandez-Medina and Javier Lopez} } @inproceedings {Roman11SK, title = {SenseKey - Simplifying the Selection of Key Management Schemes for Sensor Networks}, booktitle = {5th International Symposium on Security and Multimodality in Pervasive Environments (SMPE{\textquoteright}11)}, year = {2011}, month = {March}, publisher = {IEEE}, organization = {IEEE}, address = {Singapore}, abstract = {

Key Management Schemes (KMS) are a very important security mechanism for Wireless Sensor Networks (WSN), as they are used to manage the credentials (i.e. secret keys) that are needed by the security primitives. There is a large number of available KMS protocols in the literature, but it is not clear what should network designers do to choose the most suitable protocol for the needs of their applications. In this paper, we consider that given a certain set of application requirements, the network designer can check which properties comply with those requirements and select the KMS protocols that contains those particular properties. Therefore, we study the relationship between requirements and properties, and we provide a web tool, the SenseKey tool, that can be used to automatically obtain an optimal set of KMS protocols.

}, doi = {10.1109/WAINA.2011.78}, url = {http://www.ftrai.org/smpe2011/}, author = {Rodrigo Roman and Javier Lopez and Cristina Alcaraz and Hsiao Hwa Chen} } @article {rosado2011, title = {Systematic Design of Secure Mobile Grid Systems}, journal = {Journal of Network and Computer Applications}, volume = {34}, year = {2011}, month = {2011}, pages = {1168-1183}, publisher = {Elsevier}, abstract = {

\ Grid computing has arisen as an evolution of distributed systems mainly focused on the sharing of and remote access to resources in a uniform, transparent, secure, efficient and reliable manner. It is possible to join Grid technology and mobile technology in order to create one of the most promising technologies and developments to appear in recent years, in that they enrich one another and provide new solutions that solve many of the limitations and problems found in different technologies. Security is a very important factor in Mobile Grid Computing and is also difficult to achieve owing to the open nature of wireless networks and heterogeneous and distributed environments. Success in obtaining a secure system originates in incorporating security from the first stages of the development process. It has therefore been necessary to define a development process for this kind of systems in which security is incorporated in all stages of the development and the features and particularities of the Mobile Grid systems are taken into consideration. This paper presents one of the activities of this development process, the design activity, which consists of defining and designing a security software architecture. This architecture will be built from a security architecture, defined as reference architecture, in which security services, interfaces and operations are defined with the purpose of defining a reference security architecture which covers the majority of security requirements identified in the analysis activity. The design activity will build the system architecture that will be the input artefact for the subsequent activity in the process, which is the construction activity.

}, issn = {1084-8045}, author = {David G. Rosado and Eduardo Fernandez-Medina and Javier Lopez and Mario Piattini} } @inproceedings {Leon11, title = {Towards a Cooperative Intrusion Detection System for Cognitive Radio Networks}, booktitle = {Workshop on Wireless Cooperative Network Security (WCNS{\textquoteright}11)}, series = {LNCS}, year = {2011}, month = {May}, publisher = {Springer}, organization = {Springer}, abstract = {

Cognitive Radio Networks (CRNs) arise as a promising solution to the scarcity of spectrum. By means of cooperation and smart decisions influenced by previous knowledge, CRNs are able to detect and profit from the best spectrum opportunities without interfering primary licensed users. However, besides the well-known attacks to wireless networks, new attacks threat this type of networks. In this paper we analyze these threats and propose a set of intrusion detection modules targeted to detect them. Provided method will allow a CRN to identify attack sources and types of attacks, and to properly react against them.

}, doi = {10.1007/978-3-642-23041-7_22}, url = {http://www.networking2011.org/workshops/WCNS.html}, author = {Olga Leon and Rodrigo Roman and Juan Hernandez Serrano} } @article {rosado2009, title = {Towards a UML Extension of Reusable Secure Use Cases for Mobile Grid systems}, journal = {IEICE Trans. on Information and Systems}, volume = {E94-D}, year = {2011}, month = {Feb 2011}, pages = {243-254}, publisher = {IEICE}, abstract = {

The systematic processes exactly define the development cycle and help the development team follow the same development strategies and techniques, thus allowing a continuous improvement in the quality of the developed products. Likewise, it is important that the development process used integrates security aspects from the first stages at the same level as other functional and non-functional requirements. Grid systems allow us to build very complex information systems with different and remarkable features (interoperability between multiple security domains, cross-domain authentication and authorization, dynamic, heterogeneous and limited mobile devices, etc). With the development of wireless technology and mobile devices, the Grid becomes the perfect candidate for letting mobile users make complex works that add new computational capacity to the Grid. A methodology of development for secure mobile Grid systems is being defined. One of the activities of this methodology is the requirements analysis which is based in reusable use cases. In this paper, we will present a UML-extension for security use cases and Grid use case which capture the behaviour of this kind of systems. A detailed description of all these new use cases defined in the UML extension is necessary, describing the stereotypes, tagged values, constraints and graphical notation. We show an example of how to apply and use this extension for building the diagram of use cases and incorporating common security aspects for this kind of systems. Also, we will see how the diagrams built can be reused in the construction of others diagrams saving time and effort in this task.

}, issn = {0916-8532}, doi = {10.1587/transinf.E94.D.243}, author = {David G. Rosado and Eduardo Fernandez-Medina and Javier Lopez and Mario Piattini} } @inproceedings {Alcaraz2010, title = {Acceso seguro a redes de sensores en SCADA a trav{\'e}s de Internet}, booktitle = {XI Reuni{\'o}n Espa{\~n}ola sobre Criptolog{\'\i}a y Seguridad de la Informaci{\'o}n (RECSI 2010)}, year = {2010}, month = {September}, pages = {337-342}, address = {Tarragona (Spain)}, abstract = {

Las Infraestructuras Cr\íticas (ICs) son monitorizadas por sistemas altamente complejos, conocidos como sistemas SCADA (Sistemas de Control y Adquisici\ón de Datos), cuyo principal soporte se encuentra en las subestaciones, las cuales miden de primera instancia el estado real de tales ICs. Para mejorar este control, la industria est\á actualmente demandando la integraci\ón en el modelo tradicional de dos avances tecnol\ógicos: Internet y las redes de sensores inal\ámbricas. Sin embargo, su incorporaci\ón requiere analizar los requisitos de seguridad que surgen en dicho contexto, as\í como diversos aspectos correlacionados (ej. mantenimiento, rendimiento, seguridad y optimizaci\ón) y, en base a estos, la estrategia de integraci\ón m\ás adecuada para satisfacer dichos requisitos. Este art\ículo proporciona dicho an\álisis en profundidad con el fin de ofrecer un modelo de integraci\ón seguro adecuado para entornos cr\íticos.

}, keywords = {el Internet, Internet of Things, Redes Mesh Inal{\'a}mbrica de Sensores, Sistemas Cr{\'\i}ticos de Control, Sistemas SCADA}, isbn = {978-84-693-3304-4}, url = {http://crises-deim.urv.cat/recsi2010/}, author = {Cristina Alcaraz and Rodrigo Roman and Pablo Najera and Javier Lopez} } @article {rosado2010b, title = {Analysis of Secure Mobile Grid Systems: A Systematic Approach}, journal = {Information and Software Technology}, volume = {52}, year = {2010}, month = {May 2010}, pages = {517-536}, publisher = {Elsevier}, abstract = {

Developing software through systematic processes is becoming more and more important due to the growing complexity of software development. It is important that the development process used integrates security aspects from the first stages at the same level as other functional and non-functional requirements. Systems which are based on Grid Computing are a kind of systems that have clear differentiating features in which security is a highly important aspect. The Mobile Grid, which is relevant to both Grid and Mobile Computing, is a full inheritor of the Grid with the additional feature that it supports mobile users and resources. A development methodology for Secure Mobile Grid Systems is proposed in which the security aspects are considered from the first stages of the life-cycle and in which the mobile Grid technological environment is always present in each activity. This paper presents the analysis activity, in which the requirements (focusing on the grid, mobile and security requirements) of the system are specified and which is driven by reusable use cases through which the requirements and needs of these systems can be defined. These use cases have been defined through a UML-extension for security use cases and Grid use cases which capture the behaviour of this kind of systems. The analysis activity has been applied to a real case.

}, issn = {0950-5849}, doi = {10.1016/j.infsof.2010.01.002}, author = {David G. Rosado and Eduardo Fernandez-Medina and Javier Lopez and Mario Piattini} } @article {rofelopi, title = {Developing a Secure Mobile Grid System through a UML Extension}, journal = {Journal of Universal Computer Science}, volume = {16}, number = {17}, year = {2010}, month = {Sep 2010}, pages = {2333-2352}, publisher = {Springer}, abstract = {

The idea of developing software through systematic development processes toimprove software quality is not new. Nevertheless, there are still many information systemssuch as those of Grid Computing which are not developed through methodologies that areadapted to their most differentiating features. A systematic development process for Gridsystems that supports the participation of mobile nodes and incorporates security aspects intothe entire software lifecycle will thus play a significant role in the development of systemsbased on Grid computing. We are creating a development process for the construction ofinformation systems based on Grid Computing, which is highly dependent on mobile devices,in which security plays a highly important role. One of the activities in this process is that ofanalysis which is focused on ensuring that the system{\textquoteright}s security and functional requirements areelicited, specified and modelled. In our approach, this activity is driven by use cases andsupported by the reusable repository. This obtains, builds, defines and refines the use cases ofthe secure Mobile Grid systems which represent the functional and non-functional requirementsof this kind of systems. In this paper, we present the proposed development process throughwhich we introduce the main aspects of the UML profile defined for building use case diagramsin the mobile Grid context through which it is possible to represent specific mobile Gridfeatures and security aspects, showing in detail how to build use case diagrams for a real mobile Grid application by using our UML profile, denominated as GridUCSec-Profile.

}, issn = {0948-695x}, doi = {10.3217/jucs-016-17-2333}, author = {David G. Rosado and Eduardo Fernandez-Medina and Javier Lopez and Mario Piattini} } @inproceedings {Rios2010a, title = {Implementaci{\'o}n de un esquema de localizaci{\'o}n privada y segura para interiores}, booktitle = {IX Jornadas de Ingenier{\'\i}a Telem{\'a}tica (JITEL{\textquoteright}10)}, year = {2010}, month = {Sept.}, pages = {237 - 244}, address = {Valladolid (Spain)}, abstract = {

Las aplicaciones basadas en localizaci\ón proporcionan a los usuarios servicios personalizados dependiendo de su ubicaci\ón. Las estimaciones prev\én que estos servicios se extender\án enormemente en los pr\óximos a\ños reportando grandes beneficios tanto a la industria como a los usuarios finales. Sin embargo, para que estos avances sean posibles se hace necesario analizar en profundidad las distintas implicaciones de seguridad y privacidad que la utilizaci\ón de tales servicios pueden traer consigo a los usuarios. En este trabajo proponemos un sistema de localizaci\ón que da soporte a la provisi\ón de servicios basados en localizaci\ón para entornos indoor y que se fundamenta en la tecnolog\ía de redes de sensores inal\ámbricos. En este esquema hemos tenido en cuenta diversos aspectos de seguridad y privacidad, prestando especial atenci\ón a la limitaci\ón extrema de recursos caracter\ística de las redes de sensores. Finalmente hemos desarrollado una prueba de concepto para comprobar la viabilidad de nuestro esquema dentro del \ámbito del proyecto OSAmI.

}, isbn = {978-84-693-5398-1}, author = {Ruben Rios and Isaac Agudo and Jose L. Gonzalez}, editor = {Yannis Dimitriadis and Mar{\'\i}a Jes{\'u}s Verd{\'u} P{\'e}rez} } @article {jlopez09, title = {Los Desaf{\'\i}os de Seguridad en la Internet de los Objetos}, journal = {Revista SIC}, volume = {88}, year = {2010}, month = {Feb 2010}, pages = {66-73}, publisher = {Ediciones CODA}, abstract = {

El paradigma de la Internet de los Objetos, donde todos aquellos objetos f{\'\i}sicos que nos rodean tendr{\'a}n la capacidad de generar y consumir informaci{\'o}n en el {\'a}mbito de un mundo virtual, se encuentra cada vez m{\'a}s cerca. Es ahora un buen momento para llamar la atenci{\'o}n sobre sus principales desaf{\'\i}os de seguridad, tanto desde un punto de vista global como asociados a sus elementos m{\'a}s importantes (la tecnolog{\'\i}a RFID y las redes de sensores). As{\'\i}, este paradigma puede ser plenamente comprendido y protegido, evolucionando hacia uno de los nuevos pilares del futuro.

}, issn = {1136-0623}, author = {Javier Lopez and Rodrigo Roman and Pablo Najera} } @inproceedings {Rios2010, title = {Source Location Privacy Considerations in Wireless Sensor Networks}, booktitle = {4th International Symposium of Ubiquitous Computing and Ambient Intelligence (UCAmI{\textquoteright}10)}, year = {2010}, month = {Sept.}, pages = {29 - 38}, publisher = {IBERGARCETA PUBLICACIONES, S.L.}, organization = {IBERGARCETA PUBLICACIONES, S.L.}, address = {Valencia (Spain)}, abstract = {

Wireless Sensor Networks are considered to be one of the cornerstones of Ambient Intelligence since they can be used in countless applications, where sensors are unobtrusively embedded into the environment to perform operations like monitoring, tracking and reporting. In such scenarios, privacy issues must be carefully considered since the mere observation of the network operation might reveal great amounts of private information to unauthorised parties. One of the problems that is gaining more attention in the realm of privacy, is the location privacy problem, which aims to prevent an attacker from obtaining the location of specific nodes of interest to him. In this paper we provide a general overview of the proposed solutions to counter this threat. Finally, we will also discuss some open challenges and future directions of research for a convenient management of privacy issues in smart environments.

}, isbn = {978-84-92812-61-5}, author = {Ruben Rios and Javier Lopez}, editor = {Lidia Fuentes and Nadia G{\'a}mez and Jos{\'e} Bravo} } @inproceedings {rosado2010c, title = {A Study of Security Approaches for the Development of Mobile Grid Systems}, booktitle = {5th International Conference on Software and Data Technologies (ICSOFT{\textquoteright}10)}, volume = {1}, year = {2010}, month = {july}, pages = {133-138}, publisher = {Springer}, organization = {Springer}, address = {Athens, Greece}, abstract = {

Mobile Grid systems allow us to build highly complex information systems with various and remarkable features (interoperability between multiple security domains, cross-domain authentication and authorization, dynamic, heterogeneous and limited mobile devices, etc), which demand secure development methodologies to build quality software, offering methods, techniques and tools that facilitate the work of the entire team involved in software development. These methodologies should be supported by Grid security architectures that define the main security aspects to be considered, and by solutions to the problem of how to integrate mobile devices within Grid systems. Some approaches regarding secure development methodologies of Grid security architectures and of the integration of mobile devices in the Grid have been found in literature, and these are analyzed and studied in this paper, offering a comparison framework of all the approaches related to security in Mobile Grid environments.

}, isbn = {978-989-8425-22-5}, author = {David G. Rosado and Eduardo Fernandez-Medina and Javier Lopez} } @article {JavierLopezMunoz2010, title = {Trust Management Systems for Wireless Sensor Networks: Best practices}, journal = {Computer Communications}, volume = {33}, number = {9}, year = {2010}, pages = {0140-3664}, publisher = {Elsevier}, abstract = {

Wireless sensor networks (WSNs) have been proven a useful technology for perceiving information about the physical world and as a consequence has been used in many applications such as measurement of temperature, radiation, flow of liquids, etc. The nature of this kind of technology, and also their vulnerabilities to attacks make the security tools required for them to be considered in a special way. The decision making in a WSN is essential for carrying out certain tasks as it aids sensors establish collaborations. In order to assist this process, trust management systems could play a relevant role. In this paper, we list the best practices that we consider are essential for developing a good trust management system for WSN and make an analysis of the state of the art related to these practices.

}, issn = {0140-3664}, doi = {10.1016/j.comcom.2010.02.006}, author = {Javier Lopez and Rodrigo Roman and Isaac Agudo and Carmen Fernandez-Gago} } @inproceedings {calcaraz10, title = {Wireless Sensor Networks and the Internet of Things: Do We Need a Complete Integration?}, booktitle = {1st International Workshop on the Security of the Internet of Things (SecIoT{\textquoteright}10)}, year = {2010}, month = {December}, pages = {xxxx}, publisher = {IEEE}, organization = {IEEE}, address = {Tokyo (Japan)}, abstract = {

Wireless sensor networks (WSN) behave as a digital skin, providing a virtual layer where the information about the physical world can be accessed by any computational system. As a result, they are an invaluable resource for realizing the vision of the Internet of Things (IoT). However, it is necessary to consider whether the devices of a WSN should be completely integrated into the Internet or not. In this paper, we tackle this question from the perspective of security. While we will mention the different security challenges that may arise in such integration process, we will focus on the issues that take place at the network level.

}, issn = {xxxx}, author = {Cristina Alcaraz and Pablo Najera and Javier Lopez and Rodrigo Roman} } @inproceedings {Alcaraz2009, title = {Adaptive Dispatching of Incidences Based on Reputation for SCADA Systems}, booktitle = {6th International Conference on Trust, Privacy and Security in Digital Business (TrustBus{\textquoteright}09)}, series = {LNCS}, year = {2009}, month = {September}, pages = {86-94}, publisher = {Springer-Verlag}, organization = {Springer-Verlag}, address = {Linz, Austria}, abstract = {

SCADA systems represent a challenging scenario where the management of critical alarms is crucial. Their response to these alarms should be efficient and fast in order to mitigate or contain undesired effects. This work presents a mechanism, the Adaptive Assignment Manager (AAM) that will aid to react to incidences in a more efficient way by dynamically assigning alarms to the most suitable human operator. The mechanism uses various inputs for identifying the operators such as their availability, workload and reputation. In fact, we also define a reputation component that stores the reputation of the human operators and uses feedback from past experiences.

}, keywords = {Critical Control Systems, Reputation, Supervisory Control and Data Acquisition Systems}, isbn = {978-3-642-03747-4}, doi = {10.1007/978-3-642-03748-1_9}, author = {Cristina Alcaraz and Isaac Agudo and Carmen Fernandez-Gago and Rodrigo Roman and Gerardo Fernandez and Javier Lopez} } @inproceedings {Lopez2009, title = {Analysis of Security Threats, Requirements, Technologies and Standards in Wireless Sensor Networks}, booktitle = {Foundations of Security Analysis and Design 2009}, series = {LNCS}, volume = {5705}, year = {2009}, month = {August}, pages = {289-338}, publisher = {Springer Berlin/Heidelberg}, organization = {Springer Berlin/Heidelberg}, address = {Bertinoro (Italy)}, abstract = {

As sensor networks are more and more being implemented in real world settings, it is necessary to analyze how the different requirements of these real-world applications can influence the security mechanisms. This paper offers both an overview and an analysis of the relationship between the different security threats, requirements, applications, and security technologies. Besides, it also overviews some of the existing sensor network standards, analyzing their security mechanisms.

}, isbn = {978-3-642-03828-0}, issn = {0302-9743 (Print) 1611-3349 (Online)}, doi = {10.1007/978-3-642-03829-7_10}, url = {http://www.springerlink.com/content/u8h4882831k474n6/}, author = {Javier Lopez and Rodrigo Roman and Cristina Alcaraz} } @inproceedings {rosado2009f, title = {Applying a UML Extension to build Use Cases diagrams in a secure mobile Grid application}, booktitle = {5th International Workshop on Foundations and Practices of UML}, series = {LNCS}, volume = {5833}, year = {2009}, pages = {126-136}, publisher = {Springer Berlin Heidelberg}, organization = {Springer Berlin Heidelberg}, address = {Gramado, Brasil}, abstract = {

Systems based on Grid computing have not traditionally beendeveloped through suitable methodologies and have not taken into accountsecurity requirements throughout their development, offering technical securitysolutions only during the implementation stages. We are creating a developmentmethodology for the construction of information systems based on GridComputing, which is highly dependent on mobile devices, in which securityplays a highly important role. One of the activities in this methodology is therequirements analysis which is use-case driven. In this paper, we build use casediagrams for a real mobile Grid application by using a UML-extension, calledGridUCSec-Profile, through which it is possible to represent specific mobileGrid features and security aspects for use case diagrams, thus obtainingdiagrams for secure mobile Grid environments.

}, isbn = {978-3-642-04946-0}, author = {David G. Rosado and Eduardo Fernandez-Medina and Javier Lopez} } @inproceedings {roman2009, title = {Do Wireless Sensor Networks Need to be Completely Integrated into the Internet?}, booktitle = {3rd CompanionAble Workshop - Future Internet of People, Things and Services (IoPTS) eco-Systems}, year = {2009}, month = {December}, pages = {xxxx}, publisher = {xxxx}, organization = {xxxx}, address = {Brussels (Belgium)}, abstract = {

Wireless sensor networks are considered as an integral part of the Internet of Things paradigm. Not only they provide a virtual presence to elements of the real world, but also allow any computationalsystem to know about the physical state of those elements thanks to the use of embedded sensors. In order to belong to the Internet of Things, the elements of a sensor network can implement Internet protocols and services such as the TCP/IP stack and web services. Still, a question that must be raised at this point of time is whether all sensor network applications should be completely integrated into the Internet or not. The purpose of this paper is to analyze this question, reviewing the challenges and security requirements of Internet-enabled sensor networks.

}, issn = {xxxx}, author = {Rodrigo Roman and Javier Lopez and Cristina Alcaraz} } @inproceedings {rosado2009e, title = {Extensi{\'o}n UML para Casos de Uso Reutilizables en entornos Grid M{\'o}viles Seguros}, booktitle = {XIV Jornadas de Ingenier{\'\i}a del Software y Bases de Datos (JISBD 2009)}, year = {2009}, month = {September}, pages = {331-342}, publisher = {Antonio Vallecillo and Goiuria Sagardui (Eds.)}, organization = {Antonio Vallecillo and Goiuria Sagardui (Eds.)}, address = {San Sebasti{\'a}n, Espa{\~n}a}, abstract = {

Los sistemas Grid nos permiten construir sistemas complejos concaracter{\'\i}sticas diferenciadoras (interoperabilidad entre m{\'u}ltiples dominios deseguridad, autenticaci{\'o}n y autorizaci{\'o}n a trav{\'e}s de dominios, sistema din{\'a}micoy heterog{\'e}neo, etc.). Con el desarrollo de la tecnolog{\'\i}a wireless y losdispositivos m{\'o}viles, el Grid llega a ser el candidato perfecto para que losusuarios m{\'o}viles puedan realizar trabajos complejos, a la vez que a{\~n}aden nuevacapacidad computacional al Grid. Estamos construyendo un proceso completode desarrollo para sistemas Grid m{\'o}viles seguros, y una de las actividades es elan{\'a}lisis de requisitos, que est{\'a} basado en casos de uso reutilizables. En esteart{\'\i}culo, presentaremos una extensi{\'o}n UML para casos de uso de seguridad yGrid, los cuales capturan el comportamiento de este tipo de sistemas. Estaextensi{\'o}n UML est{\'a} siendo aplicado a un caso real para construir diagramas decasos de uso de la aplicaci{\'o}n, incorporando los aspectos de seguridadnecesarios.

}, isbn = {978-84-692-4211-7}, author = {David G. Rosado and Eduardo Fernandez-Medina and Javier Lopez} } @inproceedings {rosado2009d, title = {Hacia una Arquitectura de Servicios de Seguridad para entornos Grid m{\'o}viles}, booktitle = {V Congreso Iberoamericano de Seguridad Inform{\'a}tica (CIBSI{\textquoteright}09)}, year = {2009}, pages = {409-423}, publisher = {Universidad de la Rep{\'u}blica, Uruguay}, organization = {Universidad de la Rep{\'u}blica, Uruguay}, address = {Montevideo, Uruguay}, abstract = {

Grid m{\'o}vil incluye las caracter{\'\i}sticas de los sistemas Grid junto conlas peculiaridades de la computaci{\'o}n m{\'o}vil, a{\~n}adiendo la propiedad de soportarusuarios y recursos m{\'o}viles de forma homog{\'e}nea, transparente, segura yeficiente. La seguridad de estos sistemas, debido a su naturaleza abierta ydistribuida, es un tema de gran inter{\'e}s. Una arquitectura de seguridad basada enSOA proporciona una arquitectura distribuida dise{\~n}ada para interoperabilidadde servicios, f{\'a}cil integraci{\'o}n, y acceso seguro, simple y extensible. Por tanto,una arquitectura orientada a servicios de seguridad es construida para entornosGrid m{\'o}viles, ofreciendo servicios de seguridad a usuarios m{\'o}viles quienesusan servicios Grid y recursos para ejecutar sus trabajos y tareas. Estaarquitectura es integrada con otras arquitecturas existentes proporcionandomayor seguridad y permitiendo que los usuarios m{\'o}viles puedan acceder aservicios Grid existentes ofreciendo nuevos y necesarios servicios de seguridadpara Grid m{\'o}viles. Hemos definido un conjunto de servicios de seguridad, quejunto a protocolos, pol{\'\i}ticas y est{\'a}ndares de seguridad forman una arquitecturade seguridad orientada a servicios para entornos Grid m{\'o}viles. Esta arquitecturaes abierta, escalable, din{\'a}mica, interoperable y flexible.

}, isbn = {978-9974-0-0593-8}, author = {David G. Rosado and Eduardo Fernandez-Medina and Javier Lopez} } @article {roman2009a, title = {Integrating Wireless Sensor Networks and the Internet: A Security Analysis}, journal = {Internet Research}, volume = {19}, number = {2}, year = {2009}, month = {Mar 2009}, pages = {246-259}, publisher = {Emerald}, abstract = {

Purpose: This paper aims to analyze the security issues that arise when integrating wireless sensor networks (WSN) and the internet. Also, it seeks to review whether existing technology mechanisms are suitable and can be applied in this context.

Design/methodology/approach: The paper considers the possible approaches that can be used to connect a WSN with the internet, and analyzes the security of their interactions.

Findings: By providing the services of the network through a front-end proxy, a sensor network and the internet can interact securely. There are other challenges to be solved if the sensor nodes are integrated into the internet infrastructure, although there exists interesting advances on his matter.

Research limitations and implications: The complete integration of sensor networks and the internet still remains as an open issue.

Practical implications: With the current state of the art, it is possible to develop a secure sensor network that can provide its services to internet hosts with certain security properties.

Originality/value: The paper studies the interactions between sensor networks and the internet from the point of view of security. It identifies both solutions and research challenges.

}, keywords = {Computer networks, Data security, Integration, Internet, Wireless}, issn = {1066-2243}, doi = {10.1108/10662240910952373}, author = {Rodrigo Roman and Javier Lopez} } @article {rosado2009c, title = {Obtaining Security Requirements for a Mobile Grid System}, journal = {International Journal of Grid and High Performance Computing}, volume = {1}, year = {2009}, month = {Jan 2009}, pages = {1-17}, publisher = {IGI-Global}, abstract = {

Mobile Grid includes the characteristics of the Grid systems together with the peculiarities of Mobile Computing, withthe additional feature of supporting mobile users and resources ina seamless, transparent, secure and efficient way. Security ofthese systems, due to their distributed and open nature, isconsidered a topic of great interest. We are elaborating amethodology of development to build secure mobile grid systemsconsidering security on all life cycle. In this paper we present thepractical results applying our methodology to a real case,specifically we apply the part of security requirements analysis toobtain and identify security requirements of a specific applicationfollowing a set of tasks defined for helping us in the definition,identification and specification of the security requirements onour case study. The methodology will help us to build a securegrid application in a systematic and iterative way.

}, issn = {1938-0259}, doi = {10.4018/IJGHPC}, author = {David G. Rosado and Eduardo Fernandez-Medina and Javier Lopez} } @inproceedings {rosado2009b, title = {Reusable Security Use Cases for Mobile Grid environments}, booktitle = {Workshop on Software Engineering for Secure Systems}, year = {2009}, pages = {1-8}, publisher = {IEEE}, organization = {IEEE}, address = {Vancouver, Canada}, abstract = {

Due to the growing complexity of softwaredevelopment, developing software through systematicprocesses is becoming more and more important.Likewise, it is important that the development processused integrates security aspects from the first stages atthe same level as other functional and non-functionalrequirements. In the last years, GRID technology hasshown to be the most important one and it allows us tobuild very complex information systems with differentand remarkable features (interoperability betweenmultiple security domains, cross-domainauthentication and authorization, dynamic,heterogeneous and limited mobile devices, etc).Traditionally, systems based on GRID Computing havenot been developed through adequate methodologiesand have not taken into account security requirementsthroughout their development, only offering securitytechnical solutions at the implementation stages. Thispaper shows part of a development methodology thatwe are elaborating for the construction of informationsystems based on Grid Computing highly dependent onmobile devices where security plays a very importantrole. Specifically, in this paper, we will present theanalysis phase, managed by reusable use casesthrough which we can define the requirements andneeds of these systems obtaining an analysis modelthat can be used as input to the following phase of themethodology, the design phase of mobile Grid systems.

}, isbn = {978-1-4244-3725-2}, author = {David G. Rosado and Eduardo Fernandez-Medina and Javier Lopez} } @inproceedings {rosado2009a, title = {Reutilizaci{\'o}n de Casos de Uso en el Desarrollo de Sistemas Grid seguros}, booktitle = {XII Conferencia Iberoamericana de Ingenier{\'\i}a de Requisitos y Ambientes de Software (IDEAS{\textquoteright}09)}, year = {2009}, pages = {388-393}, publisher = {University of Colombia}, organization = {University of Colombia}, address = {Medell{\'\i}n, Colombia}, abstract = {

El desarrollo software debe estar basado en un proceso sistem{\'a}tico y estructurado donde se definan los m{\'e}todos y t{\'e}cnicas a utilizar en todo su ciclo de vida, ayudando as{\'\i} a obtener un producto de calidad. Es igualmente importante que el proceso sistem{\'a}tico considere aspectos de seguridad desde las primeras etapas, integr{\'a}ndola como un elemento m{\'a}s en el ciclo de desarrollo. En este art{\'\i}culo mostramos la metodolog{\'\i}a de desarrollo sistem{\'a}tico que sirve de gu{\'\i}a para el desarrollo de cualquier sistema Grid con dispositivos m{\'o}viles, considerando la seguridad durante todas las fases de desarrollo, lo que nos permitir{\'a} obtener como resultado sistemas Grid seguros, robustos y escalables. Este art{\'\i}culo presenta la fase de an{\'a}lisis, dirigida por casos de uso reutilizables, mediante los cuales se definen los requisitos y necesidades de estos sistemas, y es aplicada a un caso de estudio real de un Grid para el acceso de contenidos multimedia en un contexto period{\'\i}stico.

}, isbn = {978-958-44-5028-9}, author = {David G. Rosado and Eduardo Fernandez-Medina and Javier Lopez} } @inproceedings {Benito2009, title = {SMEPP: A Secure Middleware for Embedded P2P}, booktitle = {ICT Mobile and Wireless Communications Summit (ICT-MobileSummit{\textquoteright}09)}, year = {2009}, month = {June}, address = {Santander (Spain)}, abstract = {

The increasing presence of embedded devices with internet access capabilities constitutes a new challenge in software development. These devices are now cooperating in a distributed manner towards what has been called as \"Internet of Things\". In this new scenario the client-server model is sometimes not adequate and dynamic ad-hoc networks are more common than before. However, security poses as a hard issue as these systems are extremely vulnerable. In this paper, we introduce SMEPP project, which aims at developing a middleware designed for P2P systems with a special focus on embedded devices and security. SMEPP is designed to be deployed in a wide range of devices. It tries to ease the development of applications hiding platforms details and other aspects such as scalability, adaptability and interoperability. A full implementation of this middleware is already available that incorporates security features specially designed for low-resource devices. Moreover, we describe two business applications being developed using this middleware in the context of \"Digital Home\" and \"Environmental Monitoring in Industrial Environments\".

}, isbn = {978-1-905824-12-0}, author = {Rafael J. Caro and David Garrido and Pierre Plaza and Rodrigo Roman and Nuria Sanz and Jose L. Serrano} } @incollection {Roman2009b, title = {Trust and Reputation Systems for Wireless Sensor Networks}, booktitle = {Security and Privacy in Mobile and Wireless Networking}, year = {2009}, pages = {105-128}, publisher = {Troubador Publishing Ltd}, organization = {Troubador Publishing Ltd}, abstract = {

The concept of trust has become very relevant in the late years as a consequence of the growth of fields such as internet transactions or electronic commerce. In general, trust has become of paramount importance for any kind of distributed networks, such as wireless sensor networks (WSN in the following). In this chapter of the book, we try to give a general overview of the state of the art on trust management systems for WSN and also try to identify the main features of the architectures of these trust management systems.

}, isbn = {978-1905886-906}, author = {Rodrigo Roman and Carmen Fernandez-Gago and Javier Lopez and Hsiao Hwa Chen}, editor = {Stefanos Gritzalis and Tom Karygiannis and Charalabos Skianis} } @inproceedings {Alcaraz2008, title = {An{\'a}lisis de la Aplicabilidad de las Redes de Sensores para la Protecci{\'o}n de Infraestructuras de Informaci{\'o}n Cr{\'\i}ticas}, booktitle = {VI Jornadas de Ingenier{\'\i}a Telem{\'a}tica (JITEL{\textquoteright}08)}, year = {2008}, month = {September}, pages = {437}, address = {Alcal{\'a} de Henares (Spain)}, abstract = {

Las infraestructuras cr\íticas, como el sector energ\ético, la banca, el transporte, y muchas otras, son un pilar esencial para en bienestar de la sociedad y la econom\ía de un pa\ís. Estas infraestructuras dependen a su vez de ciertas infraestructuras de informaci\ón, las cuales permiten su correcto funcionamiento. La tarea de proteger esas infraestructuras (de informaci\ón) cr\íticas es compleja y multidimensional, con una gran cantidad de desaf\íos por resolver. Precisamente, las redes de sensores pueden ser de gran ayuda para esta tarea, debido a suscapacidades de control distribuidas y a su habilidad de funcionar en situaciones extremas. Este art\ículo analiza la utilidad de las redes de sensores en este contexto, describiendo tanto sus capacidades como sus posibles roles y mecanismos de integraci\ón para la protecci\ón de infraestructuras (de informaci\ón) cr\íticas.

}, isbn = {978-84-612-5474-3}, url = {http://www.telematica.ws/jitel/2008/default.htm}, author = {Cristina Alcaraz and Rodrigo Roman and Javier Lopez} } @inproceedings {Rios2008, title = {Clasificaci{\'o}n de canales encubiertos. Un nuevo canal: Covert_DHCP}, booktitle = {X Reuni{\'o}n Espa{\~n}ola de Criptolog{\'\i}a y Seguridad de la Informaci{\'o}n (RECSI{\textquoteright}08)}, year = {2008}, month = {Sept.}, pages = {325-336}, address = {Salamanca (Spain)}, abstract = {

Los canales encubiertos son una forma de comunicaci\ón oculta que puede vulnerar la integridad de los sistemas. Desde sus inicios en sistemas de seguridad multinivel a principios de los a\ños 70 han evolucionado considerablemente, apareciendo soluciones para redes de computadores debido a la especificaci\ón de algunos protocolos. Por este motivo, se hace un estudio sobre las t\écnicas que se han utilizado para crear los canales, as\í como sobre las distintos obst\áculos que han tratado de mermar su actividad. Asimismo, se presenta una nueva clasificaci\ón que trata de albergar la mayor cantidad de canales encubiertos existentes en la actualidad. Por \último, se analiza un protocolo ampliamente extendido en la actualidad, DHCP, en busca de posibilidades de albergar informaci\ón encubierta. A partir de este an\álisis se implementan distintas versiones de un canal encubierto haciendo uso de este protocolo.

}, keywords = {Canales encubiertos, control de accesos y detecci{\'o}n de intrusos, seguridad en redes, seguridad en sistemas de informaci{\'o}n}, isbn = {978-84-691-5158-7}, author = {Ruben Rios and Jose A. Onieva}, editor = {Luis Hern{\'a}ndez Encinas and Angel Martin del Rey} } @inproceedings {rosado2008a, title = {Engineering Process Based On Grid Use Cases For Mobile Grid Systems}, booktitle = {Third International Conference on Software and Data Technologies (ICSOFT{\textquoteright}08)}, year = {2008}, pages = {146-151}, publisher = {Springer}, organization = {Springer}, address = {Porto, Portugal}, abstract = {

The interest to incorporate mobile devices into Grid systems has arisen with two main purposes. The firstone is to enrich users of these devices while the other is that of enriching the own Grid infrastructure.Security of these systems, due to their distributed and open nature, is considered a topic of great interest. Aformal approach to security in the software life cycle is essential to protect corporate resources. However,little attention has been paid to this aspect of software development. Due to its criticality, security should beintegrated as a formal approach into the software life cycle. We are developing a methodology ofdevelopment for secure mobile Grid computing based systems that helps to design and build secure Gridsystems with support for mobile devices directed by use cases and security use cases and focused onservice-oriented security architecture. In this paper, we will present one of the first steps of ourmethodology consisting of analyzing security requirements of mobile grid systems. This analysis will allowus to obtain a set of security requirements that our methodology must cover and implement.

}, isbn = {978-3-642-05200-2}, issn = {1865-0929}, author = {David G. Rosado and Eduardo Fernandez-Medina and Javier Lopez and Mario Piattini} } @inproceedings {Galindo2008a, title = {An Evaluation of the Energy Cost of Authenticated Key Agreement in Wireless Sensor Networks}, booktitle = {X Reuni{\'o}n Espa{\~n}ola sobre Criptolog{\'\i}a y Seguridad de la Informaci{\'o}n (RECSI{\textquoteright}08)}, year = {2008}, month = {September}, pages = {231-236}, address = {Salamanca (Spain)}, abstract = {

Wireless sensors are battery-powered devices which are highly constrained in terms of computational capabilities, memory, and communication bandwidth. While battery life is their main limitation, they require considerable energy to communicate data. Due to this, the energy saving of computationally inexpensive security primitives (like those using symmetric key cryptography) can be nullified by the bigger amount of data they require to be sent. In this work we study the energy cost of key agreement protocols between peers in a network using public key cryptography techniques. Our concern is to reduce the amount of data to be exchanged. Our main news is that a computationally very demanding security primitive, such as identity-based authenticated key exchange, can present energy-wise a better performance than traditional public key based key exchange in realistic scenarios such as Underwater Wireless Sensor Networks. Such a result is not to be expected in wired networks.

}, author = {David Galindo and Rodrigo Roman and Javier Lopez} } @article {Alcaraz2008a, title = {Gesti{\'o}n segura de redes SCADA}, journal = {Nuevas tendencias en gesti{\'o}n de redes, Nov{\'a}tica}, number = {196}, year = {2008}, month = {December}, pages = {20-25}, publisher = {CEPIS}, abstract = {

En el momento que se introduce en el mercado nuevas tecnolog\ías basadas en entornos distribuidos comienzan a surgir en paralelo nuevos problemas de seguridad en los sistemas SCADA (Supervisory Control and Data Acquisition), los cuales monitorizan y gestionan otras infraestructuras de gran complejidad y escala. Un fallo o una interrupci\ón en uno de sus componentes podr\ía suponer un impacto negativo sobre la funcionalidad de otras infraestructuras, por lo que se hace necesario realizar frecuentes an\álisis de seguridad para as\í mantener actualizado el conocimiento y proveer recomendaciones y/o soluciones para mitigar o evitar futuras ocurrencias, garantizando una gesti\ón de red fiable y siempre disponible.

}, keywords = {An{\'a}lisis de Seguridad, Gesti{\'o}n de red SCADA, Supervisory Control and Data Acquisition Systems}, issn = {0211-2124}, url = {http://www.ati.es/novatica/indice.html$\#$196}, author = {Cristina Alcaraz and Gerardo Fernandez and Rodrigo Roman and Angel Balastegui and Javier Lopez} } @incollection {Roman2008, title = {On the Hardware Implementation Efficiency of Cryptographic Primitives}, booktitle = {Wireless Sensor Network Security}, year = {2008}, publisher = {IOS Press}, organization = {IOS Press}, abstract = {

Security has been proven a crucial factor in the provision of data services and especially in the computer-related environments. While wired and wireless networks come to all sectors of everyday life, security tries to satisfy the growing needs for confidentiality, integrity and non-repudiation. There are many instances of security primitives and each one of them has different requirements in terms of processing power, word size, etc. Therefore, it is important to review the functionality of the less resource-demanding encryption algorithms in order to analyze their theoretical suitability to the existent sensor node hardware. Still, the constraints inherent to the sensor nodes advise against the total dependence on software-based implementations, even more in the case of expensive primitives.

}, isbn = {978-1-58603-813-7}, author = {Rodrigo Roman and Cristina Alcaraz and Nicolas Sklavos}, editor = {Javier Lopez and Jianying Zhou} } @inproceedings {Roman2008b, title = {KeyLED - Transmitting Sensitive Data over out-of-band Channels in Wireless Sensor Networks}, booktitle = {5th IEEE International Conference on Mobile Ad Hoc and Sensor Systems (MASS{\textquoteright}08)}, year = {2008}, month = {September}, pages = {796-801}, publisher = {IEEE}, organization = {IEEE}, address = {Atlanta (USA)}, abstract = {

An out-of-band (OoB) channel can be defined as an extra channel, different from the main wireless channel, that has additional security properties. They are specially suitable for protecting spontaneous interactions and exchanging sensitive data between previously unknown devices. Due to the vulnerable nature of wireless sensor networks (WSN), these kind of channels might be useful for protecting certain sensor network operations. In this paper we analyze the applicability of out-of-band channels to wireless sensor networks, and specify why an optical channel should be a good candidate for implementing an extra channel in sensor nodes. Also, we analyze how the existing security threats may affect this type of channel. Finally, the suitability and usability of optical channels for sensor networks is demonstrated by means of a prototype.

}, keywords = {Out-of-Band Channel, security, wireless sensor networks}, isbn = {978-1-4244-2574-7}, doi = {10.1109/MAHSS.2008.4660128}, author = {Rodrigo Roman and Javier Lopez} } @inproceedings {Galindo2008aa, title = {A Killer Application for Pairings: Authenticated Key Establishment in Underwater Wireless Sensor Networks}, booktitle = {Proceedings of the 7th International Conference on Cryptology and Network Security (CANS{\textquoteright}08)}, series = {LNCS}, volume = {5339}, year = {2008}, month = {December}, pages = {120-132}, publisher = {Springer}, organization = {Springer}, address = {Hong Kong (China)}, abstract = {

Wireless sensors are low power devices which are highly constrained in terms of computational capabilities, memory, and communication bandwidth. While battery life is their main limitation, they require considerable energy to communicate data. The latter is specially dramatic in underwater wireless sensor networks (UWSN), where the acoustic transmission mechanisms are less reliable and more energy-demanding. Saving in communication is thus the primary concern in underwater wireless sensors. With this constraint in mind, we argue that non-interactive identity-based key agreement built on pairings provides the best solution for key distribution in large UWSN when compared to the state of the art. At first glance this claim is surprising, since pairing computation is very demanding. Still, pairing-based non-interactive key establishment requires minimal communication and at the same time enjoys excellent properties when used for key distribution.

}, keywords = {identity-based key agreement, key distribution, pairings, underwater wireless sensor networks}, isbn = {978-3-540-89640-1}, issn = {0302-9743 (Print) 1611-3349 (Online)}, doi = {10.1007/978-3-540-89641-8_9}, url = {http://www.springerlink.com/content/g26h0115ngt12331/}, author = {David Galindo and Rodrigo Roman and Javier Lopez} } @inproceedings {Benito2008, title = {Middleware Seguro EP2P: un Desaf{\'\i}o para las Redes Sociales}, booktitle = {XVIII Jornadas Telecom I+D}, year = {2008}, month = {October}, address = {Bilbao (Spain)}, abstract = {

Los sistemas distribuidos en dispositivos embebidos representan un nuevo reto en el desarrollo de software. Estos sistemas han supuesto una importante revoluci{\'o}n en el paradigma de la computaci{\'o}n distribuida donde se intenta fragmentar un problema grande en m{\'u}ltiples problemas m{\'a}s peque{\~n}os. El nuevo escenario tiende entonces hacia sistemas en los cuales todos los elementos de la red se consideran iguales y los mecanismos de comunicaci{\'o}n est{\~a}n basados en redes ad-hoc que se forman din{\'a}micamente. De esta forma cualquier usuario de la red (en realidad cualquier elemento, hasta el m{\'a}s simple dispositivo) adquiere valor, a mayor colaboraci{\'o}n, mayor {\'e}xito del sistema. Sin embargo, desde el punto de vista de la seguridad, estos sistemas son extremadamente vulnerables. En este art{\'\i}culo se presenta SMEPP, un middleware dise{\~n}ado especialmente para sistemas P2P incluyendo aspectos de seguridad. SMEPP est{\'a} dise{\~n}ado para poder ser ejecutado en un amplio rango de dispositivos (desde redes de sensores hasta PC), y trata de facilitar el desarrollo de aplicaciones ocultando los detalles de la plataforma y otros aspectos tales como escalabilidad, adaptabilidad e interoperabilidad. Adem{\'a}s el art{\'\i}culo presenta dos aplicaciones de alto nivel que utilizando este middleware pasan a ser m{\'a}s personales, m{\'a}s sociales y m{\'a}s baratas, haciendo que todos los usuarios de la red cobren mayor importancia.

}, author = {Rafael J. Caro and David Garrido and Pierre Plaza and Rodrigo Roman and Nuria Sanz and Jose L. Serrano} } @inproceedings {rosado2008, title = {PSecGCM: Process for the development of Secure Grid Computing based Systems with Mobile devices}, booktitle = {International Conference on Availability, Reliability and Security (ARES{\textquoteright}08)}, year = {2008}, pages = {136-143}, publisher = {IEEE Computer Society}, organization = {IEEE Computer Society}, address = {A Grid computing system is defined as a platform that supports distributed system applications which require fast access to a large quantity of distributed resources in a coordinated manner. With the development of wireless technology and mobile devices,}, abstract = {

A Grid computing system is defined as a platformthat supports distributed system applications which require fastaccess to a large quantity of distributed resources in acoordinated manner. With the development of wirelesstechnology and mobile devices, the Grid becomes the perfectcandidate so that mobile users can make complex works that addnew computational capacity to the Grid. Security of thesesystems, due to their distributed and open nature, receives greatinterest. The growing size and profile of the grid requirecomprehensive security solutions as they are critical to thesuccess of the endeavour. A formal approach to security in thesoftware life cycle is essential to protect corporate resources.However, little thought has been given to this aspect of softwaredevelopment. Due to its criticality, security should be integratedas a formal approach in the software life cycle. A methodology ofdevelopment for secure mobile Grid computing based systems isdefined, that is to say, an engineering process that defines thesteps to follow so that starting from the necessities to solve, wecan design and construct a secure Grid system with support formobile devices that is able to solve and cover these necessities.

}, issn = {978-0-7695-3102-1}, author = {David G. Rosado and Eduardo Fernandez-Medina and Javier Lopez and Mario Piattini} } @article {Alcaraz2008b, title = {Secure Management of SCADA Networks}, journal = {Novatica, New Trends in Network Management}, volume = {9}, number = {6}, year = {2008}, month = {December}, pages = {22-28}, publisher = {Cepis UPGRADE}, abstract = {

When a Supervisory Control and Data Acquisition (SCADA) system monitors and manages other complex infrastructures through the use of distributed technologies, it becomes a critical infrastructure by itself: A failure or disruption in any of its components could implicate a serious impact on the performance of the other infrastructures. The connection with other systems makes a SCADA system more vulnerable against attacks, generating new security problems. As a result, it is essential to perform diverse security analysis frequently in order to keep an updated knowledge and to provide recommendations and/or solutions to mitigate or avoid anomalous events. This will facilitate the existence of a suitable, reliable, and available control network.

}, keywords = {SCADA network management, Security Analysis, Supervisory Control and Data Acquisition Systems}, issn = {1684-5285}, url = {http://www.upgrade-cepis.org/issues/2008/6/up9-6Alcaraz.pdf}, author = {Cristina Alcaraz and Gerardo Fernandez and Rodrigo Roman and Angel Balastegui and Javier Lopez} } @article {Roman2008a, title = {Situation Awareness Mechanisms for Wireless Sensor Networks}, journal = {IEEE Communications Magazine}, volume = {46}, number = {4}, year = {2008}, month = {April}, pages = {102-107}, publisher = {IEEE}, abstract = {

A wireless sensor network should be able to operate for long periods of time with little or no external management. There is a requirement for this autonomy: the sensor nodes must be able to configure themselves in the presence of adverse situations. Therefore, the nodes should make use of situation awareness mechanisms to determine the existence of abnormal events in their surroundings. This work approaches the problem by considering the possible abnormal events as diseases, thus making it possible to diagnose them through their symptoms, namely, their side effects. Considering these awareness mechanisms as a foundation for high-level monitoring services, this article also shows how these mechanisms are included in the blueprint of an intrusion detection system.

}, issn = {0163-6804}, doi = {10.1109/MCOM.2008.4481348}, author = {Rodrigo Roman and Javier Lopez and Stefanos Gritzalis} } @inproceedings {Alcaraz2007, title = {An{\'a}lisis de primitivas criptogr{\'a}ficas para redes de sensores}, booktitle = {VI Jornadas de Ingenier{\'\i}a Telem{\'a}tica (JITEL{\textquoteright}07)}, year = {2007}, month = {September}, pages = {401-408}, address = {M{\'a}laga (Spain)}, abstract = {

Security in wireless sensor networks is very limited due to highly-constrained hardware of sensor nodes. To protect services is necessary to use secure foundations, known as security primitives, like part of a protocol. Theses primitives must assure at least confidentiality in the communication channel, authentication of the peers involved in an information exchange, and integrity of the messages. There are many primitives such as symmetric encryption, hash functions and public key cryptography, but not all of them can be supported by sensor nodes since require high resource levels, for example memory. This paper contains a deep analysis of available and suitable security primitives for sensor nodes, as well as an analysis of hardware and software implementations. Besides, it has been developed an experiment with two implementations, and it has been created a new and improved version using the optimizations of each.

}, isbn = {978-84-690-6670-6}, url = {http://www.telematica.ws/jitel/2007/}, author = {Cristina Alcaraz and Rodrigo Roman and Javier Lopez} } @inproceedings {Roman2007b, title = {Applicability of Public Key Infrastructures in Wireless Sensor Networks}, booktitle = {European PKI Workshop: Theory and Practice (EuroPKI{\textquoteright}07)}, series = {LNCS}, volume = {4582}, year = {2007}, month = {June}, pages = {313-320}, publisher = {Springer}, organization = {Springer}, address = {Mallorca (Spain)}, abstract = {

Wireless Sensor Networks (WSN) are becoming a key technology in the support of pervasive and ubiquitous services. The previous notion of PKC is too expensive for WSN has changed partially due to the existence of new hardware and software prototypes based on Elliptic Curve Cryptography and other PKC primitives. Then, it is necessary to analyze whether it is both feasible and convenient to have a Public Key Infrastructure for sensor networks that would allow the creation of PKC-based services like Digital Signatures.

}, keywords = {Public Key Cryptography, Public Key Infrastructure, wireless sensor networks}, isbn = {978-3-540-73407-9}, issn = {0302-9743 (Print) 1611-3349 (Online)}, doi = {10.1007/978-3-540-73408-6_22}, url = {http://www.springerlink.com/content/q4l10ww348010131/}, author = {Rodrigo Roman and Cristina Alcaraz} } @article {Zhou2007, title = {An Effective Multi-layered Defense Framework Against Spam}, journal = {Information Security Technical Report}, volume = {12}, number = {3}, year = {2007}, pages = {179-185}, publisher = {Elsevier}, abstract = {

Spam is a big problem for email users. The battle between spamming and anti-spamming technologies has been going on for many years. Though many advanced anti-spamming technologies are progressing significantly, spam is still able to bombard many email users. The problem worsens when some anti-spamming methods unintentionally filtered legitimate emails instead! In this paper, we first review existing anti-spam technologies, then propose a layered defense framework using a combination of anti-spamming methods. Under this framework, the server-level defense is targeted for common spam while the client-level defense further filters specific spam for individual users. This layered structure improves on filtering accuracy and yet reduces the number of false positives. A sub-system using our pre-challenge method is implemented as an add-on in Microsoft Outlook 2002. In addition, we extend our client-based pre-challenge method to a domain-based solution thus further reducing the individual email users{\textquoteright} overheads.

}, keywords = {Network Security, Security service, Spam}, issn = {1363-4127}, doi = {10.1016/j.istr.2007.05.007}, url = {http://www.sciencedirect.com/science/article/B6VJC-4NS2GR9-1/2/d542b6d1b936f796cad17284a6edbc69}, author = {Jianying Zhou and Wee-Yung Chin and Rodrigo Roman and Javier Lopez} } @inproceedings {Roman2007c, title = {Featuring Trust and Reputation Management Systems for Constrained Hardware Devices}, booktitle = {1st International Conference on Autonomic Computing and Communication Systems (Autonomics{\textquoteright}07)}, year = {2007}, month = {October}, publisher = {ICST}, organization = {ICST}, address = {Rome (Italy)}, abstract = {

Research on trust management systems for wireless sensor networks is still at a very early stage and few works have done so far. It seems that for those works which deal with the topic general features of how these systems should be are not clearly identified. In this paper we try to identify the main features that a trust management system should have and justify their importance for future developments.

}, keywords = {Sensor Networks, Trust Management}, isbn = {978-963-9799-09-7}, author = {Rodrigo Roman and Carmen Fernandez-Gago and Javier Lopez} } @inproceedings {Rosado2007, title = {Hacia un Proceso sistem{\'a}tico para el desarrollo de sistemas Grid Seguros con Dispositivos M{\'o}viles}, booktitle = {IV Congreso Iberoamericano de Seguridad Inform{\'a}tica (CIBSI{\textquoteright}07)}, year = {2007}, pages = {111-124}, publisher = {Sebasti{\'a}n Ca{\~n}{\'o}n, M.A.}, organization = {Sebasti{\'a}n Ca{\~n}{\'o}n, M.A.}, address = {Mar del Plata, Argentina}, isbn = {978-950-623-043-2}, author = {David G. Rosado and Eduardo Fernandez-Medina and Javier Lopez and Mario Piattini} } @inproceedings {M.MagdalenaPayerasCapella2007, title = {Incompatibilidades entre Propiedades de los Protocolos de Intercambio Equitativo de Valores}, booktitle = {VI Jornadas de Ingenier{\'\i}a Telem{\'a}tica (JITEL{\textquoteright}07)}, year = {2007}, pages = {605-608}, publisher = {Universidad de Malaga}, organization = {Universidad de Malaga}, abstract = {

Sets of ideal properties are defined for different kinds of protocols designed for e-commerce applications. These sets are used as a start point in the design and then as a tool to evaluate the quality of the protocols. This is the case of fair exchange protocols and their application to electronic contract signing and certified electronic mail. However, in this area does not exist an agreement about which properties are ideal. Instead we can find properties described by different authors to his convenience. We illustrate the contradictions that appear between some of these properties.

}, author = {Magdalena Payeras and Josep L. Ferrer Gomila and Lloren Huguet Rotger and Jose A. Onieva} } @article {JoseA.Onieva2007a, title = {Integration of non-repudiation services in mobile DRM scenarios}, journal = {Telecommunications Systems}, volume = {35}, year = {2007}, month = {September}, pages = {161-176}, abstract = {

In any kind of electronic transaction, it is extremely important to assure that any of the parties involved can not deny their participation in the information exchange. This security property, which is called non-repudiation, becomes more important in Digital Rights Management (DRM) scenarios, where a consumer can freely access to certain contents but needs to obtain the proper Right Object (RO) from a vendor in order to process it. Any breach in this process could result on financial loss for any peer, thus it is necessary to provide a service that allows the creation of trusted evidence. Unfortunately, non-repudiation services has not been included so far in DRM specifications due to practical issues and the type of content distributed. In this paper we analyze how to allow the integration of non-repudiation services to a DRM framework, providing a set of protocols that allows the right objects acquisition to be undeniable, alongside with a proof-of-concept implementation and a validation process.

}, keywords = {digital rights management, Mobile applications, Non-repudiation, Secure electronic commerce}, issn = {1572-9451}, author = {Jose A. Onieva and Javier Lopez and Rodrigo Roman and Jianying Zhou and Stefanos Gritzalis} } @incollection {Lopez2007, title = {On the Protection and Technologies of Critical Information Infrastructures.}, booktitle = {On Foundations of Security Analysis and Design IV, FOSAD 2006/2007, Springer}, series = {LNCS}, volume = {4677}, year = {2007}, note = {

10.1007/978-3-540-74810-6_6

}, pages = {160-182}, abstract = {

Critical Infrastructures are complex and highly interconnected systems that are crucial for the well-being of the society. Any type of failure can cause significant damage, affecting one or more sectors due to their inherent interdependency. Not only the infrastructures are critical, but also the information infrastructures that manage, control and supervise them. Due to the seriousness of the consequences, the protection of these critical (information) infrastructures must have the highest priority. It is the purpose of this book chapter to review and discuss about these infrastructures, to explain their elements, and to highlight their research and development issues. This chapter will also discuss the role of Wireless Sensor Network (WSN) technology in the protection of these infrastructures.

}, keywords = {Critical Information Infrastructure Protection, wireless sensor networks}, issn = {0302-9743}, doi = {10.1007/978-3-540-74810-6_6}, url = {http://dx.doi.org/10.1007/978-3-540-74810-6_6}, author = {Javier Lopez and Cristina Alcaraz and Rodrigo Roman} } @article {Roman2007a, title = {The Role of Wireless Sensor Networks in the Area of Critical Information Infrastructure}, journal = {Information Security Technical Report}, volume = {12}, number = {1}, year = {2007}, pages = {24-31}, publisher = {Elsevier}, abstract = {

Critical Infrastructures, such as energy, banking, and transport, are an essential pillar to the well-being of the national and international economy, security and quality of life. These infrastructures are dependent on a spectrum of highly interconnected information infrastructures for their smooth, reliable and continuous operation. The field of protecting such Critical Information Infrastructures, or CIIP, faces numerous challenges, such as managing the secure interaction between peers, assuring the resilience and robustness of the overall system, and deploying warning and alert systems, amongst others. In this tapestry of CIIP, Wireless Sensor Networks can be used as an invaluable tool due to their intelligent distributed control capabilities, alongside with their capability to work under severe conditions. In this paper, we justify why Wireless Sensor Networks technology is suitable for providing security for these scenarios, describing both their advantages and research issues and their role in the overall scheme of protecting the Critical Information Infrastructures.

}, keywords = {Critical Information Infrastructure Protection, Network Security, wireless sensor networks}, issn = {1363-4127}, doi = {10.1016/j.istr.2007.02.003}, url = {http://www.sciencedirect.com/science/article/B6VJC-4N6NK24-1/2/b1462973afe70af30a10b955d96ccbb6}, author = {Rodrigo Roman and Cristina Alcaraz and Javier Lopez} } @article {Roman2007, title = {A Survey of Cryptographic Primitives and Implementations for Hardware-Constrained Sensor Network Nodes}, journal = {Mobile Networks and Applications}, volume = {12}, number = {4}, year = {2007}, month = {August}, pages = {231-244}, publisher = {Springer}, abstract = {

In a wireless sensor network environment, a sensor node is extremely constrained in terms of hardware due to factors such as maximizing lifetime and minimizing physical size and overall cost. Nevertheless, these nodes must be able to run cryptographic operations based on primitives such as hash functions, symmetric encryption and public key cryptography in order to allow the creation of secure services. Our objective in this paper is to survey how the existing research-based and commercial-based sensor nodes are suitable for this purpose, analyzing how the hardware can influence the provision of the primitives and how software implementations tackles the task of implementing instances of those primitives. As a result, it will be possible to evaluate the influence of provision of security in the protocols and applications/scenarios where sensors can be used.

}, keywords = {Cryptography, Hardware, Sensor Networks}, issn = {1383-469X}, doi = {10.1007/s11036-007-0024-2}, url = {http://www.springerlink.com/content/3785k818327456gq/}, author = {Rodrigo Roman and Cristina Alcaraz and Javier Lopez} } @inproceedings {FernandezGago2007, title = {A Survey on the Applicability of Trust Management Systems for Wireless Sensor Networks}, booktitle = {3rd International Workshop on Security, Privacy and Trust in Pervasive and Ubiquitous Computing (SecPerU{\textquoteright}07)}, year = {2007}, pages = {25-30}, publisher = {IEEE Computer Society}, organization = {IEEE Computer Society}, address = {Istanbul (Turkey)}, abstract = {

Trust plays an important role in human life environments and virtual organizations. In the context of a network, trust may help its elements to decide whether another member of the same network is being uncooperative or malicious. Trust becomes quite important in self-configurable and autonomous systems, such as wireless sensor networks (WSN). However, very little effort has been done in the field of trust management in WSN. On the other hand, some efforts have been made in quite related fields such as Ad-hoc and P2P networks. In this paper we give an overview of existing trust management solutions, mainly those developed for Ad-Hoc and P2P networks and, more importantly, investigate their suitability to WSN. We also provide some guidelines to aid the development of trust management systems for WSN according to the nature of these networks.

}, doi = {10.1109/SECPERU.2007.3}, author = {Carmen Fernandez-Gago and Rodrigo Roman and Javier Lopez} } @article {Roman2006a, title = {An Anti-spam Scheme Using Pre-challenges}, journal = {Computer Communications}, volume = {29}, number = {15}, year = {2006}, pages = {2739-2749}, publisher = {Elsevier}, abstract = {

Unsolicited Commercial Email, or Spam, is nowadays an increasingly serious problem to email users. A number of anti-spam schemes have been proposed in the literature and some of them have been deployed in email systems, but the problem has yet been well addressed. One of those schemes is challenge-response, in which a challenge, ranging from a simple mathematical problem to a hard-AI problem, is imposed on an email sender in order to forbid machine-based spam reaching receivers{\textquoteright} mailboxes. However, such a scheme introduces new problems for the users, e.g., delay of service and denial of service. In this paper, we introduce the pre-challenge scheme, which is based on the challenge-response mechanism and takes advantage of some features of email systems. It assumes each user has a challenge that is defined by the user himself/herself and associated with his/her email address, in such a way that an email sender can simultaneously retrieve a new receiver{\textquoteright}s email address and challenge before sending an email in the first contact. Some new mechanisms are employed in our scheme to reach a good balance between security against spam and convenience to normal email users. Our scheme can be also used for protecting other messaging systems, like Instant Messaging and Blog comments.

}, keywords = {Anti-spam, Electronic mail, Internet security}, issn = {0140-3664}, doi = {10.1016/j.comcom.2005.10.037}, url = {http://www.sciencedirect.com/science/article/B6TYP-4HYM1T7-1/2/53871c3a06d8e1c9439deda17a05ed2d}, author = {Rodrigo Roman and Jianying Zhou and Javier Lopez} } @inproceedings {Roman2006, title = {Applying Intrusion Detection Systems to Wireless Sensor Networks}, booktitle = {IEEE Consumer Communications \& Networking Conference (CCNC 2006)}, year = {2006}, month = {January}, pages = {640-644}, publisher = {IEEE}, organization = {IEEE}, address = {Las Vegas (USA)}, abstract = {

The research of Intrusion Detection Systems (IDS) is a mature area in wired networks, and has also attracted many attentions in wireless ad hoc networks recently. Nevertheless, there is no previous work reported in the literature about IDS architectures in wireless sensor networks. In this paper, we discuss the general guidelines for applying IDS to static sensor networks, and introduce a novel technique to optimally watch over the communications of the sensors{\textquoteright} neighborhood on certain scenarios.

}, isbn = {1-4244-0085-6}, doi = {10.1109/CCNC.2006.1593102}, author = {Rodrigo Roman and Jianying Zhou and Javier Lopez} } @inproceedings {Alcaraz2006, title = {Applying Key Infrastructures for Sensor Networks in {CIP/CIIP} Scenarios}, booktitle = {1st International Workshop on Critical Information Infrastructures Security (CRITIS{\textquoteright}06)}, series = {LNCS}, volume = {4347}, year = {2006}, pages = {166-178}, publisher = {Springer Berlin / Heidelberg}, organization = {Springer Berlin / Heidelberg}, abstract = {

It is commonly agreed that Wireless Sensor Networks (WSN) is one of the technologies that better fulfills features like the ones required by Critical (Information) Infrastructures. However, a sensor network is highly vulnerable against any external or internal attacks, thus network designers must know which are the tools that they can use in order to avoid such problems. In this paper we describe in detail a procedure (the KMS Guidelines), developed under our CRISIS project, that allows network designers to choose a certain Key Management System, or at least to know which protocol need to improve in order to satisfy the network requirements.

}, keywords = {Critical Information Infrastructures, Key Infrastructures, Key Management, Sensor Networks}, issn = {0302-9743 (Print) 1611-3349 (Online)}, doi = {10.1007/11962977_14}, url = {http://www.springerlink.com/content/2458827107n14870/}, author = {Cristina Alcaraz and Rodrigo Roman} } @inproceedings {JoseA.Onieva2006a, title = {Extension de una plataforma DRM basada en OMA con servicios de No Repudio}, booktitle = {IX Reunion Espa{\~n}ola sobre Criptologia y Seguridad de la Informacion (RECSI{\textquoteright}06)}, year = {2006}, pages = {129-141}, publisher = {UOC S.L.}, organization = {UOC S.L.}, abstract = {

Digital Rights Management (DRM) es un t\érmino general para cualesquiera de las soluciones que permite a un vendedor de contenido en forma electr\ónica controlar el material y restringir su uso de distintas maneras. Estas soluciones son posibles, por un lado gracias a t\écnicas de la Seguridad de la Informaci\ón, principalmente cifrado de datos, y por otro a la distribuci\ón, de manera independiente, de contenido y derechos digitales. Esto permite que los consumidores puedan acceder libremente al contenido, pero s\ólo aquellos que adquieran el derecho digital apropiado (RO) podr\án procesarlo. Como servicio de seguridad considerado en diversas capas del marco de seguridad definido por la recomendaci\ón ITU X.805, casi todas las aplicaciones necesitan considerar la propiedad de no repudio en las etapas iniciales de su dise\ño. Desafortunadamente, esto no ha sido as\í en general, y m\ás concretamente en especificaciones DRM; debido a consideraciones en la pr\áctica y al tipo de contenido a distribuir. Analizamos este servicio para un marco de DRM y proporcionamos una soluci\ón que permita que la adquisici\ón de derechos digitales sea un operaci\ón que no pueda repudiarse.

}, keywords = {aplicaciones moviles, comercio electronico seguro, digital rights management, no repudio}, author = {Jose A. Onieva and Javier Lopez and Rodrigo Roman and Jianying Zhou} } @inproceedings {JavierLopez2006a, title = {Service-Oriented Security Architecture for CII based on Sensor Networks}, booktitle = {2nd International Workshop on Security Privacy and Trust in Pervasive and Ubiquitous Computing (SecPerU{\textquoteright}06)}, year = {2006}, month = {June}, pages = {1-6}, publisher = {IEEE Press}, organization = {IEEE Press}, address = {Lyon, France}, abstract = {

The extraordinary growth of the Information Society is originating a high dependency on ICT. This provokes that those strongly interrelated technological infrastructures, as well as the information systems that underpin them, become highly critical, since their disruption would lead to high economical, material and, sometimes, human loss. As a consequence, the protection of these Critical Information Infrastructures is becoming a major objective for governments and companies. In this paper, we give an overview of the main challenges and open research issues on Critical Information Infrastructure security, and introduce an on-going research project that, using wireless sensor networks as an underlying technology, is dealing with those problems. Our research project focuses on the development of protection, control, evaluation, maintenance and verification mechanisms, integrated into a secure service-oriented architecture.

}, author = {Javier Lopez and Jose A. Montenegro and Rodrigo Roman} } @inproceedings {R.Roman2005, title = {An{\'a}lisis de Seguridad en Redes Inal{\'a}mbricas de Sensores}, booktitle = {V Jornadas de Ingener{\'\i}a Telem{\'a}tica (JITEL{\textquoteright}05)}, year = {2005}, month = {Septiembre}, pages = {335-343}, address = {Vigo (Spain)}, abstract = {

The design and development of security infrastructures and protocols for Wireless Sensor Networks is a difficult task, due to several factors like the constraints of the sensor nodes and the public nature of the communication channels. The intrinsic features of these networks create numerous security problems. In this paper, we analyze and put into perspective those problems.

}, author = {Rodrigo Roman and Javier Lopez and Jianying Zhou} } @inproceedings {Roman2005b, title = {Aplicaci{\'o}n de Sistemas de Detecci{\'o}n de Intrusiones en Redes de Sensores}, booktitle = {Simposio sobre Computaci{\'o}n Ubicua e Inteligencia Ambiental (UCAmI{\textquoteright}05)}, year = {2005}, month = {September}, pages = {113-120}, address = {Granada (Spain)}, abstract = {

Los sistemas de detecci{\'o}n de intrusiones (IDS) son una herramienta imprescindible de seguridad a la hora de proteger una red. Recientemente se han investigado y desarrollado arquitecturas de IDS para redes inal{\'a}mbricas, en concreto para redes "Ad Hoc". No obstante, no existe un trabajo previo que desarrolle una arquitectura de IDS para una red de sensores. En este art{\'\i}culo, analizamos porque los sistemas IDS de redes "Ad Hoc" no pueden aplicarse a redes de sensores, e introducimos una arquitectura de IDS para redes de sensores que incorpora una nueva t{\'e}cnica para vigilar las comunicaciones de la red en ciertos escenarios.

}, author = {Rodrigo Roman and Javier Lopez and Jianying Zhou} } @article {Roman2005f, title = {Casual Virtual Private Network}, journal = {International Journal of Computer Systems Science \& Engineering}, volume = {3}, year = {2005}, pages = {185-192}, publisher = {CRL Publishing}, abstract = {

Virtual Private Networks (VPNs) provide a cost-effective way for securing communications using public and insecure networks like the Internet. The main purpose of a VPN is to securely and transparently connect two or more remote networks to form virtually a single network, using centralized security policies for better management and protection. However, in certain scenarios, users may not require such a transparent access to the resources within their networks, but only want temporary secure access to internal services based on their own demands. We call the network architecture with such a feature as Casual VPN. In this paper, we present the notion of Casual VPN, and explain why traditional VPN architectures and protocols are unable to offer Casual VPN services. We also propose and define the operation of a particular Casual VPN architecture, C-VPN, which additionally allows the management of TCP and UDP-based protocols.

}, issn = {0267-6192}, author = {Rodrigo Roman and Jianying Zhou and Javier Lopez} } @inproceedings {Roman2005c, title = {Especificaci{\'o}n de Sistemas Electr{\'o}nicos de Microdonaciones}, booktitle = {III Simposio Espa{\~n}ol de Comercio Electr{\'o}nico}, year = {2005}, month = {June}, pages = {95-104}, address = {Palma (Spain)}, abstract = {

Los sistemas electr{\'o}nicos de pago permiten que un comprador adquiera a un vendedor una serie de productos y servicios de forma virtual. Sin embargo, estos sistemas no tienen en cuenta el escenario en el que un comprador se convierte en donante, accediendo al servicio de forma gratuita. En este art{\'\i}culo se presenta el concepto y caracter{\'\i}sticas de las microdonaciones, o la donaci{\'o}n de cantidades tan peque{\~n}as como un c{\'e}ntimo de euro en el contexto del comercio electr{\'o}nico. Tambi{\'e}n se muestra como la microdonaci{\'o}n es algo necesario en el contexto actual de Internet, y como es posible su implementaci{\'o}n bas{\'a}ndose en sistemas de micropago.

}, author = {Rodrigo Roman and Javier Lopez} } @inproceedings {Onieva2005, title = {Extending an OMA-based DRM Framework with Non-Repudiation Services}, booktitle = {5th Symposium on Signal Processing and Information Technology (ISSPIT{\textquoteright}05)}, year = {2005}, pages = {472-477}, publisher = {IEEE}, organization = {IEEE}, abstract = {

Digital Rights Management (DRM) is an umbrella term for any of several arrangements which allows a vendor of content in electronic form to control the material and restrict its usage in various ways that can be specified by the vendor. These arrangements are provided through security techniques, mainly encryption, and the distribution, in a detached manner, of content and rights. This allows free access to the content by the consumers, but only those carrying the proper Right Object (RO) will be able to process such content. As a security service considered in different layers of the security framework defined by ITU X.805, almost all applications need to consider non-repudiation in the very beginning of their design. Unfortunately this has not been done so far in DRM specifications due to practical issues and the type of content distributed. We analyze this service for the a DRM framework and provide a solution which allows the right objects acquisition to be undeniable.

}, keywords = {digital rights management, Mobile applications, Non-repudiation, Secure electronic commerce}, author = {Jose A. Onieva and Jianying Zhou and Javier Lopez and Rodrigo Roman} } @inproceedings {Roman2005a, title = {Protecci{\'o}n contra el Spam Utilizando Desaf{\'\i}os a Priori}, booktitle = {V Jornadas de Ingenier{\'\i}a Telem{\'a}tica (JITEL{\textquoteright}05)}, year = {2005}, month = {September}, pages = {375-382}, address = {Vigo (Spain)}, abstract = {

Spam is considered to be one of the biggest problems in messaging systems. In the area of email Spam, A high number of anti-spam schemes have been proposed and deployed, but the problem has yet been well addressed. In this paper, we introduce a new scheme, called pre-challenge scheme, which avoids problems that exists in other schemes such as delay of service and denial of service. Some new mechanisms are employed to reach a good balance between security against Spam and convenience to email users. In addition, our scheme can be used for protecting other types of messaging systems, such as Instant Messaging (IM) and Blogs, against Spam.

}, author = {Rodrigo Roman and Javier Lopez and Jianying Zhou} } @inproceedings {Roman2005d, title = {Protection Against Spam using Pre-Challenges}, booktitle = {20th IFIP International Information Security Conference (IFIP-SEC{\textquoteright}05)}, year = {2005}, month = {May}, pages = {281-294}, publisher = {Springer}, organization = {Springer}, address = {Chiba (Japan)}, abstract = {

Spam turns out to be an increasingly serious problem to email users. A number of anti-spam schemes have been proposed and deployed, but the problem has yet been well addressed. One of those schemes is challenge-response, in which a challenge is imposed on an email sender. However, such a scheme introduces new problems for the users, e.g., delay of service and denial of service attacks. In this paper, we introduce a pre-challenge scheme that avoids those problems. It assumes each user has a challenge that is defined by the user himself/herself and associated with his/her email address, in such a way that an email sender can simultaneously retrieve a new receiver{\textquoteright}s email address and challenge before sending an email in the first contact. Some new mechanisms are employed to reach a good balance between security against spam and convenience to email users.

}, isbn = {0-387-25658-X}, author = {Rodrigo Roman and Jianying Zhou and Javier Lopez}, editor = {Ry{\^o}ichi Sasaki and Sihan Qing and Eiji Okamoto and Hiroshi Yoshiura} } @inproceedings {Roman2005e, title = {On the Security of Wireless Sensor Networks}, booktitle = {Computational Science and Its Applications (ICCSA{\textquoteright}05)}, series = {LNCS}, volume = {3482}, year = {2005}, month = {May}, pages = {681-690}, publisher = {Springer}, organization = {Springer}, address = {Singapore}, abstract = {

Wireless Sensor Networks are extremely vulnerable against any kind of internal or external attacks, due to several factors such as resource-constrained nodes and lack of tamper-resistant packages. As a result, security must be an important factor to have in mind when designing the infrastructure and protocols of sensor networks. In this paper we survey the state-of-the-art security issues in sensor networks and highlight the open areas of research.security issues in sensor networks and highlight the open areas of research.

}, isbn = {978-3-540-25862-9}, issn = {0302-9743 (Print) 1611-3349 (Online)}, doi = {10.1007/11424857_75}, url = {http://www.springerlink.com/content/pvnd4eu8b7acgtpe/}, author = {Rodrigo Roman and Jianying Zhou and Javier Lopez} } @inproceedings {EijiOkamoto2003, title = {Certificate Retrieval and Validation in Online Systems}, booktitle = {Symposium on Cryptography and Information Security (SCIS{\textquoteright}03)}, year = {2003}, month = {January}, pages = {25-30}, address = {Hamamatsu, Japan}, abstract = {

In order to more effectively deal with certificate management issues in PKIs, there is growing interest in supplementing offline X.509 PKI models with online services. An analysis of the security requirements of online models will be presented. Proposed online and delegated processing models will be evaluated in relation to these requirements.

}, author = {Eiji Okamoto and Javier Lopez and Ed Dawson and Juan M. Gonzalez-Nieto and Selwyn Russell and Jason Smith} } @article {SelwynRusell2003, title = {Virtual Certificates and Synthetic Certificates: New Paradigms for Improving Public Key Validation}, journal = {Computer Communications}, volume = {26}, number = {16}, year = {2003}, pages = {1826-1838}, publisher = {Elsevier}, abstract = {

The certificate paradigm is applied recursively to obtain the public keys of a number of Certification Authorities and, accordingly, to obtain the public keys of a number of final entities. Thus, validation of the authorized public key of a party in a network transaction is commonly based on processing the certificate chain descended from a trusted root issuer, involving non-negligible time and cost. Those chains become long in communications between large organizations, which is the typical case of e-commerce and e-government applications. The process of validation of extensive chains introduces performance problems in two aspects: signature verification and revocation checking. That is, the repeated processing of long chains of certificates creates severe efficiency problems. This fact causes that most of the advantages provided by Public Key Infrastructures (PKIs) are not conveniently exploited. In this paper we analyze the scenarios in which large volumes of digitally signed transactions between commercial entities exist. These cases require of interoperation among PKIs. We show that solutions available in those scenarios still involve processing of too long chains of certificates, either at the receiving computer or by an outsourced entity. For this reason, we propose new concepts of virtual certificate and synthetic certificate for faster and less costly processing of certificate chains. In this way, communications in a certificate-based intercommunity can be highly improved. We also show how these types of certificates can be applied in practice.

}, issn = {0140-3664}, author = {Selwyn Rusell and Ed Dawson and Eiji Okamoto and Javier Lopez} } @inproceedings {JavierLopez2002c, title = {Design of a VPN Software Solution Integrating TCP and UDP Services}, booktitle = {International Conference on Infrastructure Security (InfraSec{\textquoteright}02)}, series = {LNCS}, volume = {2437}, year = {2002}, month = {October}, pages = {325-337}, publisher = {Springer-Verlag}, organization = {Springer-Verlag}, address = {Bristol, U.K.}, abstract = {

The main aims of Virtual Private Network (VPN) are to isolate a distributed network from outsiders, as well as to protect the confidentiality and integrity of sensitive information traversing a non-trusted network such as the Internet. However, some problems arise when security is considered as the unique problem because VPN users suffer from restrictions in their access to the network. They are not free to use traditional Internet services such as electronic mail exchange with non-VPN users, and to access Web and FTP servers external to the organization. This paper presents a new solution that allows the open use of traditional network services running over TCP and UDP layers, while maintaining strong security features. The new scheme works at the TCP/IP transport layer and does not require the addition of new hardware because it is a totally software solution. As a consequence, the application is totally portable. Moreover, and because of its implementation at the transport layer, there is no need to modify any traditional communication applications previously installed in the network system.

}, author = {Javier Lopez and Jose A. Montenegro and Rodrigo Roman and Jorge Davila} } @inproceedings {SelwynRussell2002, title = {Improving Performance in Global PKI using Virtual Certificates and Synthetic Certificates}, booktitle = {Symposium on Cryptography and Information Security (SCIS{\textquoteright}02)}, year = {2002}, month = {January}, pages = {1149-1154}, abstract = {

A digital certificate may be used to inform the world of the public key of its owner. To guard against impersonations and fraud, the receiver needs to perform a series of checks. When a hierarchy of certificates is involved, and when there are large volumes of messages between two parties, as is frequent in commerce, the repeated validation of the same chain of certificates consume significant resources. This paper presents new concepts of virtual certificate and synthetic certificate which can be used to speed up repetitive processing of a chain with improved efficiency.

}, author = {Selwyn Russell and Eiji Okamoto and Ed Dawson and Javier Lopez} } @inproceedings {1736, title = {Online Public Key Infrastructure}, booktitle = {VII Reuni{\'o}n Espa{\~n}ola sobre Criptolog{\'\i}a y Seguridad de la Informaci{\'o}n (VII RECSI)}, year = {2002}, month = {Sep 2002}, pages = {123-135}, address = {Oviedo (Spain)}, isbn = {84-699-8930-8}, author = {W. Caelli and K. Chen and E. Dawson and M. Henricksen and Javier Lopez and E. Okamoto and S. Russell and J. Smith} } @inproceedings {JorgeDavila2001, title = {Introducci{\'o}n de Aplicaciones UDP en Redes Privadas Virtuales}, booktitle = {III Jornadas de Ingenier{\'\i}a Telem{\'a}tica (JITEL{\textquoteright}01)}, year = {2001}, month = {Septiembre}, pages = {397-404}, address = {Barcelona (Spain)}, abstract = {

Virtual Private Network (VPN) solutions mainly focus on security aspects. However, when security is considered the unique problem, some collateral ones arise. VPN users suffer from restrictions in their access to the network. They are not free to use traditional Internet services such as electronic mail exchange and audio/video conference with non-VPN users, and to access Web and Ftp servers external to the organization. In this paper we present a new solution, located at the TCP/IP transport layer and oriented to UDP applications that, while maintaining strong security features, allows the open use of traditional network services. The solution does not require the addition of new hardware because it is an exclusively software solution. As a consequence, the application is totally portable.

}, author = {Jorge Davila and Javier Lopez and Rodrigo Roman} } @article {1714, title = {Dise{\~n}o de Protocolos de No-Repudio}, journal = {Revista SIC: Seguridad en Inform{\'a}tica y Comunicaciones}, volume = {38}, year = {2000}, pages = {1-5}, issn = {1136-0623}, author = {Jorge Davila and Javier Lopez and Felipe Rosello} } @inproceedings {JavierLopez1999d, title = {Problem{\'a}tica de Seguridad para el Comercio Electr{\'o}nico en el Sector Tur{\'\i}stico}, booktitle = {I Congreso Nacional Turismo y Tecnolog{\'\i}a de la Informaci{\'o}n y las Comunicaciones (TURITEC{\textquoteright}99)}, year = {1999}, month = {Septiembre}, pages = {99-110}, abstract = {

Uno de los servicios que cada d\ía cobra m\ás importancia y que promete un cambio radical para las empresas es el comercio electr\ónico en Internet, pero tradicionalmente las empresas relacionadas con el turismo s\ólo han empleado la red para darse a conocer y ofertar sus productos. La raz\ón esencial es la desconfianza que existe sobre la seguridad de las transacciones llevadas a cabo en la red. La criptograf\ía de clave p\ública proporciona servicios adecuados para garantizar la seguridad de esas transacciones. Pero en la actualidad, algunos de esos servicios est\án menos desarrollados que otros; un ejemplo de ellos es el servicio de No-Repudio. En este art\ículo se estudian distintas formas de ofrecer servicios de no-repudio y se analizan sus ventajas y desventajas en funci\ón de las necesidades del entorno en que se utilicen.

}, author = {Javier Lopez and Javier Areitio and Felipe Rosello} } @article {GonzaloRamos1998, title = {Comparisons of Parikh{\textquoteright}s conditions to other conditions for context-free languages}, journal = {Theoretical Computer Science}, volume = {202}, number = {1-2}, year = {1998}, pages = {231-244}, publisher = {Elsevier}, abstract = {

this paper we first compare Parikh\’s condition to various pumping conditions\ - Bar- Hillel\’s pumping lemma, Ogden\’s condition and Bader-Moura\’s condition; secondly, to interchange condition; and finally, to Sokolowski\’s and Grant\“s conditions. In order to carry out these comparisons we present some properties of Parikh\’s languages. The main result is the orthogonality of the previously mentioned conditions and Parikh\’s condition.

In

}, issn = {0304-3975}, author = {Gonzalo Ramos and Javier Lopez and Rafael Morales} } @inproceedings {JavierLopez1996a, title = {Comparaci{\'o}n de la Condici{\'o}n de Parikh con algunas Condiciones de los Lenguajes de Contexto Libre}, booktitle = {II Jornadas de Inform{\'a}tica y Autom{\'a}tica}, year = {1996}, month = {Julio}, pages = {305-314}, address = {Almu{\~n}ecar, Espa}, abstract = {

In this paper we first compare Parikh\’s condition to various pumping conditions - Bar-Hillel\’s pumping lemma, Ogden\’s condition and Bader-Moura\’s condition; secondly, to interchange condition; and finally, to Sokolowski\’s and Grant\’s conditions. In order to carry out these comparisons we present some properties of Parikh\’s languages. The main result is the orthogonality of the previously mentioned conditions and Parikh\’s condition.

}, author = {Javier Lopez and Gonzalo Ramos and Rafael Morales} } @inproceedings {GonzaloRamos1996, title = {ID3f+A. Algoritmo de Aprendizaje Inductivo Borroso con Divisi{\'o}n Intervalar Autom{\'a}tica de los Atributos}, booktitle = {VI Congreso Espa{\~n}ol Sobre Tecnolog{\'\i}as y L{\'o}gica Fuzzy (ESTYLF{\textquoteright}96)}, year = {1996}, month = {Septiembre}, pages = {225-230}, abstract = {

Uno de los campos m\ás prometedores dentro del estudio de la ambig\üedad es el del aprendizaje, tanto por su importancia consusntacial como por su relaci\ón con la Inteligencia Artificial. Esta relaci\ón se hace evidente cuando intentamos resolver, desde una perspectiva borrosa, el problema de la adquisici\ón autom\ática del conocimiento en sistemas expertos. El algoritmo ID3, el m\ás relevante de los utilizados para la inducci\ón de \árboles de decisi\ón, no es utilizable tal cual con un concepto borroso del concepto de pertenencia. Adem\ás se muestra ineficiente cuando no existe un experto humano que defina correctamente los subrangos de actuaci\ón para los atributos que junto a las clases expresan las relaciones entre situaciones que este algoritmo de aprendizaje intenta descubrir. Proponemos como soluci\ón un nuevo algoritmo, el ID3f+A, que posee la capacidad de tratamiento borroso del concepto de pertenencia, gracias a una modificaci\ón del concepto de entrop\ía, y adem\ás realiza la divisi\ón intervalar autom\ática de los atributos, merced al control del proceso inductivo por medio de la utilizaci\ón de experiencias de control.

}, author = {Gonzalo Ramos and Javier Lopez} }