    @article {Onieva2004c,
	title = {Non-repudiation Protocols for Multiple Entities},
	journal = {Computer Communications},
	volume = {27},
	number = {16},
	year = {2004},
	pages = {1608-1616},
	abstract = {<p>Non-repudiation is a security service that provides cryptographic evidence to support the settlement of disputes. In this paper, we introduce the state-of-the-art of non-repudiation protocols for multiple entities. We extend an existing multi-party non-repudiation (MPNR) protocol to allow an originator to send different messages to many recipients in a single transaction. We further propose an optimistic multi-party non-repudiation protocol for exchange of different messages. The performance of our protocols with enhanced functionalities is still promising in comparison with existing MPNR protocols.</p>},
	keywords = {Electronic commerce, fair exchange, group communications, Non repudiation, Security protocol},
	issn = {0140-3664},
	author = {Jose A. Onieva and Jianying Zhou and Javier Lopez}
}
