A Low Cost and Reliable Anonymity Scheme in P2P Reputation Systems with Trusted Third Parties

In this paper, we present an anonymity scheme to achieve all the peers´ anonymity in P2P reputation systems by changing pseudonym with the help of a trusted third party (TTP) server, such that neither the TTP server nor other peers can link each peer´s pseudonyms. Compared with RuP, an existing representative scheme, our scheme has two main features. First, the TTP server´s cost is reduced by more than half in terms of numbers of RSA decryption operations and message overhead, which makes our scheme be more scalable. Second, we also propose a reputation metric that can be integrated into P2P reputation systems that achieve peers´ anonymity by changing pseudonym, to help estimate the trustworthiness of peers. Simulation results show the effectiveness of our proposed reputation metric.