@article {Agudo2020, title = {A Blockchain Approach for Decentralized V2X (D-V2X)}, journal = {IEEE Transactions on Vehicular Technology}, volume = {70}, number = {5}, year = {2021}, month = {05/2021}, pages = {4001 - 4010}, publisher = {IEEE}, abstract = {

New mobility paradigms have appeared in recent years, and everything suggests that some more are coming. This fact makes apparent the necessity of modernizing the road infrastructure, the signalling elements and the traffic management systems. Many initiatives have emerged around the term Intelligent Transport System (ITS) in order to define new scenarios and requirements for this kind of applications. We even have two main competing technologies for implementing Vehicular communication protocols (V2X), C-V2X and 802.11p, but neither of them is widely deployed yet.

One of the main barriers for the massive adoption of those technologies is governance. Current solutions rely on the use of a public key infrastructure that enables secure collaboration between the different entities in the V2X ecosystem, but given its global scope, managing such infrastructure requires reaching agreements between many parties, with conflicts of interest between automakers and telecommunication operators. As a result, there are plenty of use cases available and two mature communication technologies, but the complexity at the business layer is stopping the drivers from taking advantage of ITS applications.

Blockchain technologies are defining a new decentralized paradigm for most traditional applications, where smart contracts provide a straightforward mechanism for decentralized governance. In this work, we propose an approach for decentralized V2X (D-V2X) that does not require any trusted authority and can be implemented on top of any communication protocol. We also define a proof-of-concept technical architecture on top of a cheap and highly secure System-on-Chip (SoC) that could allow for massive adoption of D-V2X.\ 

}, issn = {0018-9545}, doi = {10.1109/TVT.2020.3046640}, author = {Isaac Agudo and Manuel Montenegro-G{\'o}mez and Javier Lopez} } @article {nunez2014blindidm, title = {BlindIdM: A Privacy-Preserving Approach for Identity Management as a Service}, journal = {International Journal of Information Security}, volume = {13}, year = {2014}, pages = {199-215}, publisher = {Springer}, abstract = {

Identity management is an almost indispensable component of today{\textquoteright}s organizations and companies, as it plays a key role in authentication and access control; however, at the same time it is widely recognized as a costly and time-consuming task. The advent of cloud computing technologies, together with the promise of flexible, cheap and efficient provision of services, has provided the opportunity to externalize such a common process, shaping what has been called Identity Management as a Service (IDaaS). Nevertheless, as in the case of other cloud-based services, IDaaS brings with it great concerns regarding security and privacy, such as the loss of control over the outsourced data. In this paper we analyze these concerns and propose BlindIdM, a model for privacy-preserving IDaaS with a focus on data privacy protection. In particular, we describe how a SAML-based system can be augmented to employ proxy re-encryption techniques for achieving data con dentiality with respect to the cloud provider, while preserving the ability to supply the identity service. This is an innovative contribution to both the privacy and identity management landscapes.

}, issn = {1615-5262}, doi = {10.1007/s10207-014-0230-4}, author = {David Nu{\~n}ez and Isaac Agudo} } @article {CSI13, title = {Building Trust from Context Similarity Measures}, journal = {Computer Standards \& Interfaces, Special Issue on Security in Information Systems}, volume = {36}, year = {2014}, pages = {792-800}, publisher = {Elsevier}, abstract = {

\ Trust is an essential feature of any system where entities have to\ collaborate among them. Trust can assist entities making decisions\ about what is the best entity for establishing a certain collaboration.\ It would be desirable to simulate behaviour of users as in social environments\ where they tend to establish relationships or to trust users\ who have common interests or share some of their opinions, i.e., users\ who are similar to them to some extent. Thus, in this paper we first\ introduce the concept of context similarity among entities and from it\ we derive a similarity network which can be seen as a graph. Based\ on this similarity network we dene a trust model that allows us also\ to establish trust along a path of entities. A possible applications of\ our model are proximity-based trust establishment. We validate our model in this scenario.

}, issn = {0920-5489}, doi = {10.1016/j.csi.2013.12.012}, author = {Carmen Fernandez-Gago and Isaac Agudo and Javier Lopez} }