关键词: 对等网络, 动态综合评价, 信任模型, 模糊综合评价

Abstract: According to the deficiency of trust model employed by the existing P2P netwok， which inadquately consider the difference and the dynamic in peers’ behavior when aggregating the peer trust， a new dynamic fuzzy comprhensive trust model (DFCTrust) was proposed in this paper， that is the time attemiation factor and the fluctuation punisive measure were added on the basis of static fuzzy comprehensive evaluation. In the model， the satisfactory degree of every transction was firstly computed by static fuzzy comprehensive evaluation. Attribute to taking the transction context factor into consideration， the model is good at avoiding the malicious act which is trust in small transction while distrust in large one. Secondly， because the time attemiation factor and the fluctuation punisive measure were added when aggregating peertrust， the model do well not only in reducing the failure due to trading with inactive peers but also in resisting the periodic oscillation cheating from malicious peers. Simulation experiment shows that DFCTrust has good dynamic adaptive ability to cope whith the behavior changes with strategy and then can improve transction success rate.

Key words: Peer to Peer (P2P) network, dynamic comprehensive evaluation, trust model, Fuzzy evaluation method