Research On Trust Update Mechanism In Peer-to-Peer Network

With the rapid development of P2P(Peer-to-Peer) network, the main problem needs to be solved is how to guarantee the safety of interaction. Trust system has been proved one of the most effective technology to solve the security problem. But the trust update mechanism in the current trust system is still not perfect, which degrade the actual availability of the trust system in P2P network. In this paper, we incorporate the trust context and the preferences of different agents with the trust update mechanism, and by using the theory of trust propagation, we propose a new trust update mechanism which gives more availability to the trust system in the environment of changing context and considering the difference of user preferences.In this paper, we comprehensively analyze the trust system and several common advantages and disadvantages of the current trust update mechanism, and then propose a new trust update algorithm which based on trust context and user preferences. Firstly, we modeling the trust context, and incorporate it into the trust update mechanism, through the use of trust propagation theory, we propose the first trust update algorithm CBTU(Context Based Trust Update). Secondly, we considering the difference of user preferences and use it in the trust update algorithm, then proposed the second trust update algorithm PBTU(Preferences Based Trust Update). Thirdly, we combine both trust context and user preferences with trust update mechanism, and proposed CPBTU (Context-Preferences Based Trust Update Mechanism). Experiments show that in the case of changing context and considering user preferences, the algorithm we proposed has highly effective performance in trust updating than common trust update methods.