Journal of Xidian University
A fair multi-party exchange protocol with theoff-line trusted third party
Jianzhong Zhang
Abstract
The difference between the fair exchange protocols and the non-repudiation protocols is proposed. Based on the publicly verifiable secret sharing scheme and group encryption scheme, a new multi-party fair exchagne protocol with an off-line semi-Trusted Third Party(off-STTP) is presented. The off-STTP who need not be completely trusted intervenes into the exchange in case of trouble. That the off-STTP can only decipher a sub-secret key makes sure the confidentiality of exchange data and the true fairness of the barter. The participants can barter with others at their will and the exchange topology is unknown to others including the off-STTP.