Abuse-free fair exchange protocol without TTP
摘要
Based on the improved perfect concurrent signature,this paper proposed an abuse-free fair exchange protocol without trusted third party.This protocol avoided the flaw,by which buyer could prove to others that he has done an artificial trade with the shop,existed in other fair exchange protocols based on perfect concurrent signature.In the proposed protocol,buyer and shop bound the order information,payment information,and digital content together in the ambiguity signature which could be verified publicly after the buyer released extra keystones.And the buyer could get the key from the shop to decrypt the cipher of the digital content he wanted after he released keystones.The keystones bound the ambiguity signature,deal information of the buyer and shop together to avoid any one of the signer abuse these information.This protocol could be used in P2P network in which it's hard to find a trusted third party.Also using this protocol could avoid the risk that third party cooperating with one party to cheat others and avoid the performance bottleneck caused by third party.