A Trust Model Of P2P Network Based On Group

Security model of Peer-to-Peer networks is one of hottest research in current academic field. Due to the unfitness of the traditional centralized trust mechanism to the demand of P2P system, it is necessary to establish a distributed trust mechanism to enhance the dependability of P2P system. As the most important components in trust mechanism, trust model emphasizes the trusted member in group and trusted data, and ensures members of using resource of network more rationally through annunciating and restricting the improper actions.According to the analysis of advantages and disadvantages of existing local trust model and global trust model in this paper,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 between groups and peers and trust relationship among peers in the same group. In a group,evaluations between members come into being by combinations of history records of object peers written by members and individual experience of appreciators,also by amending these records according to differences of individuals'abilities to remark. In P2P network,trust evaluation between groups are obtained by using a method of global trust. At last,trust degree of aim peers is calculated by evaluations between members in the same group and trust evaluations between groups, then decision of trade is made by the trust degree.The simulation results show that the model makes few mistakes in the process of searching target, so it is more safe when malicious peers attack and it pays out less loss in the changing and convergency process of network topology.