Research Of Trust Model Based On P2P

With the wide applications of P2P software, security in P2P network has been a hot point in research, and trust mechanism is very important in P2P network. Trust model is kernel of the trust mechanism, which makes the calculation and processing of trust very flexible, so that it can be adaptable to the changes of network environment.First, with deep study of subjective logic, Josang proposes and uses the subjective logic to model the trust relations, and it introduces the fact space and opinion space to describe and calculate the trust relations. But the subjective logic model does not consider the influence of time attenuation and negative events on the trust value, so it can not eliminate the malicious recommendations. Aiming at these disadvantages, this thesis introduces time attenuation and negative events to improve the subjective logic, giving the trust quantization formula with forgetting factor.Second,based on the improving sunjactive logic,a evaluation of trust value based on reputation and risk is proposed, with hidden uncertainty as the trust append.Lastly,a trust model TABTM based on agent is proposed.It divides P2P network into several 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 trust evaluation of reputation and risk,and trust value of agent is calculated by all peers in the group.Results of experiments show that the TABTM trust model can evaluate the trust of peers more exactly and prevent the security hidden danger of cooperative cheat and slander, so that it can solve the security problems in P2P network environment more effectively,...