A New Fair Multi-party Exchange Protocol
一种新型的多方公平交换协议

The fair exchange protocols are classified. Based on publicly verifiable secret sharing scheme and group encryption scheme, a new multi-party fair exchange protocol with an off-line Semi-Trusted Third Party(off-STTP) is presented. The off-STTP intervenes into the exchange in case of problems. That the off-STTP can 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.