The Research Of Trust Model In P2P

P2P is peer-to-peer network, which is a newly emerging computing model brought by popularization of network, and pursue the effective utilize of information resource in network. The peers in P2P are equal, and each of them plays two roles, both the role of file provider and the role of a peer. Although this system structure provides a powerful means to locate and share desired information over the Internet, they also bring up some problems with ceaseless application widen and deepen, eg. security issues. Trust model is an important approach to make sure the security of P2P. Trust model established in P2P guarantees the system security and service dependability, consequently, it will enhance the security and reliability of network. Server peer should be encouraged to provide good service in system, also client peer should be encouraged to supply fair-minded evaluation.Firstly, we put forward a new searching source arithmetic by importing trust of peers, this arithmetic will be used to filter the malicious peers, and reduce the chance to build a link with malicious peers when client-peers want to select service-peers and make a service. At result it makes sure the service quality. In this arithmetic, we also consider the accouts of redundancy package that peer received, and the improved searching resource peers algorithm can reduce the redundancy packages received by peers, what's more, it can enhance the reliability of system.Secondly, we propose a trust model based on the improved searching source arithmetic. At beginning time, trust value changes quickly when it updates the trust value in existing trust model, so the beginning evaluation of malicious peers or distrustful peers will affect peer's trust strongly. In this paper, we propose an improved trust model which provides a new method to update the trust value. This approach applies logarithm for evaluation and counts of services to compute the trust based on the anonymity of network, and it prevents malicious peers from attacking the normal peers and trust peers efficiently, meanwhile it restrains the malicious peers from increasing their trust respectively by their group collaboration. Furthermore, we consider the condition that a new peer joins the system in this trust model. In this joining arithmetic, we import load balance, which can make the load of every peer equate as much as possible, and reduce the chance that some peers paralyze due to the exceeding loads in P2P. Finally, trust model proposed in this paper is simulated by JADE, and the simulating datas prove that this trust model has better service quality, also reduce the feasibility which is attacked by malicious peers than existing trust model. Furthermore, it is enhanced system security and success ratio of searching.