A Fair Transaction Mechanism for P2P File-Sharing Applications

In P2P file-sharing applications, distributed virtual payment mechanism is designed to encourage resource sharing among peers and thus restrain free-riding behaviors. However, it does not provide any protection on the security of the transaction process and the quality of the trading contents. We design a fair transaction mechanism for P2P file-sharing applications, in which a trusted third party is constructed and used to guarantee the atomic operation of the file-money exchange, in virtue of the property of distributed payment mechanism. The trading file is signed with the seller´s private key, which can be used as proof in case of dissension. Performance analysis indicates that the costs of fair transaction mechanism are limited in both trading session latency and overhead to the system.