Identity crisis: anonymity vs reputation in P2P systems

The effectiveness of reputation systems for peer-to-peer resource-sharing networks is largely dependent on the reliability of the identities used by peers in the network. Much debate has centered around how closely one´s pseudo-identity in the network should be tied to their real-world identity, and how that identity is protected from malicious spoofing. We investigate the cost in efficiency of two solutions to the identity problem for peer-to-peer reputation systems. Our results show that, using some simple mechanisms, reputation systems can provide a factor of 4 to 20 improvement in performance over no reputation system, depending on the identity model used.