An efficient non-repudiation protocol

Fairness may be a desirable property of a non-repudiation service. Protocols can achieve fairness through the involvement of a trusted third party but the extent of the trusted third party's involvement can vary between protocols. Hence, one of the goals of designing an efficient non-repudiation protocol is to reduce the workload of the trusted third party. In this paper, we present a variant of our fair non-repudiation protocol (1996), where the trusted third party is involved only in the case that one party cannot obtain the expected non-repudiation evidence from the other party. This variant is efficient in an environment where the two parties are likely to resolve communications problems between themselves.