A Subjective Trust Model of P2P Network Based on Reputation and Risk

P2P systems have a dynamic open and anonymous characteristic, which restricts P2P system of cooperation between the users and system reliability and availability. A subjective trust model of P2P network based on reputation and risk is presented to solve the problem. Taking into account the influence on the calculation of confidence at different periods of trading, time decay function which different weight is distributed in accordance with the trading range of different periods has been introduced into this model. And at the same time, taking into account uncertainty that the dynamic behavior of the nodes effects the calculation of confidence, the risk factors have been introduced, which makes the impact of node trust by the malicious acts more sensitive through adjusting weight of credibility of the value and risk value appropriately. The simulation experiments and analysis shows that the model is able to reject malicious behaviors such as slander and conspiracy, and increase the successful proportion of transactions of the system.