A Group Based Reputation System for P2P Networks

In large scale P2P networks, it is less likely that repeat interactions will occur between same peers for the asymmetric interests between them. So it is difficult to establish the direct trust relationship between peers and the network is vulnerable to malicious peers. A group based reputation system GroupRep for P2P networks is proposed in this paper to solve this problem. In GroupRep, the trust relationship is classified into three tiers: the trust relationship between groups, between groups and peers, and between peers. A peer evaluates the credibility of a given peer by its local trust information or the reference from the group it belonging to. A filtering cluster algorithm is proposed to filter unfair ratings provided by malicious peers. As a result, good peers are distinguished from malicious ones. Choosing the download source based on the trust value of responders can make good peers happy with the high ratio of the success query and the high satisfaction level under malicious collusive attacks with front peers.