The Research Of Trust Mechanism Based On P2P Network Security

P2P service has become the one of the most important applications in the Internet nowadays. However, the nature of openness, anonymity and loose-coupling relationship between peers in P2P networks leads to a complete lack of responsibility for the content a peer puts on the network, opening the door to abuses of these networks by malicious peers. Moreover high dynamics of peer behaviors always bring on unsteadiness of the network bandwidth and performance. Therefore, it is necessary to build trust relationship between peers in the distributed large-scale P2P networks.According to the analysis of advantages and disadvantages of existing local trust model and global trust model in paper, In view of large-scale network between peers because the interest is asymmetrical has redundant transaction possible, trust model management based on group is put forward, which is created by reference to process of trust establishment in real society and management of firms and cooperation between firms. The trust model pays attention to the guiding meaning of trust evaluation. It divides P2P network into several overlapped groups with different functions and treats it as trust relationship of groups, trust relationship among peers in the same group. In a group, The trust value of a peer from the viewpoint of another in a group is computed based on the reputation, while that of a gravity peer in the group is evaluated by global trust value. In P2P network, trust evaluation between groups are obtained by using a method of global trust.Simulation about the model was developed to investigate it is performance. 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 with the high ratio of the success query and the high satisfaction level under various attacks of malicious peers.