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A Pseudonym Changing-Based Anonymity Protocol for P2P Reputation Systems

In this paper, we present an anonymity protocol to achieve all the peers’ anonymity in P2P reputation systems by changing pseudonym with the help of a trusted third party (TTP) server. Compared with RuP, an existing representative scheme, our protocol has three main features. First, the TTP server’s cost is reduced by more than half in terms of numbers of RSA decryption operations without increasing message overhead. Second, unlike RuP where peers’ anonymity is not achievable in two specific cases, our proposed protocol eliminated this limitation. Third, we also propose a reputation metric that can be integrated into anonymity protocols for P2P reputation systems based on changing pseudonym, to help estimate the trustworthiness of peers. Simulation results show the effectiveness of our proposed reputation metric.