Research On Reputation System Of File Sharing In P2P Environment

The resources in P2P networks are not dependable because of the open and anonymity nature of P2P networks, some malicious peers may propagate viruses and Trojan horses via P2P networks. In this paper, the approach of trust and reputation systems is used to solve the trustworthiness problems of resource providers in P2P networks, so as to avoid downloading resources blindly.In this paper, some reputation systems in P2P environment at present are analyzed, such as Xrep, PeerTrust, Pablano, etc, and an enhanced reputation system is designed. The designed reputation system consists of a trust evaluation module and a secure transport protocol. Contrast to most reputation systems, not only more comprehensive factors are considered on evaluating trust, but also divides trust into a few states, the algorithm of evaluating trust is different at different trust state. So, the trust value is more precise and reasonable. In this paper, we analyze the security of the designed reputation system, and simulate the system by java programs. From the result of simulation, it can be proved that the success rate of peers' interactions with our reputation system is not only greatly improved contrast to without, but also better than Pablano reputation system, especially when there are a lot of malicious peers.Finally, automated trust negotiation is introduced to the application of reputation system, in other words, the method based on trust evaluation and the method based on credentials are integrated, then the approaches of integration are discussed. It is concluded that the introduction of automated trust negotiation has reduced the risk of depending on reputation systems only, so the dependability of sensitive information transportation is guaranteed.