With the phenomenal growth of the Internet and open networks in general, security services, such as non-repudiation, become crucial to many applications. Nonrepudiation services must ensure that when Alice sends some information to Bob over a network, neither Alice nor Bob can deny having participated in a part or the whole of this communication. Therefore a fair non-repudiation protocol has to generate non-repudiation of origin evidences intended to Bob, and non-repudiation of receipt evidences destined to Alice. In this paper, we clearly define the properties a fair non-repudiation protocol must respect, and give a survey of the most important non-repudiation protocols without and with trusted third party (TTP). For the later ones we discuss the evolution of the TTP's involvement and, between others, describe the most recent protocol using a transparent TTP. We also discuss some ad-hoc problems related to the management of non-repudiation evidences.

this technical report, the result has been announced and a brief sketch of the proof has been given by Even when presenting a contract signing protocol [60] in 1981. This result enforces the intuition that it is impossible to "simultaneously" exchange two items, without a "referee"

This paper presents a novel protocol for achieving secure and fair document exchange among multiparties