Trust Model Based On P2p Networks

With the rapid development and popularization of Internet, the Peer-to-Peer(P2P)network technology developes rapidly nowadays. The traditional network centres onits contents with a model of C/S, and the P2P network adopts a distributing networkstructure, and each peer is both client and server. This infrastructure is widely used infile-sharing, distributed computation, cooporation system, deep search engine andelectrical business, etc. At present, the P2P network is under developing without aamature standard. With the distributed characteristic, P2P network lacks centralizedcontrol and its safety becomes a outstanding problem. Although it is convenient to theshared resources, but the facticity of the resources is not ensured especially in the P2Pfile sharing system. Moreover, the P2P system with open and anonymous characteradmits the entrance and departure of any peer, some evil peers could do harm to thesystem and enhance the unsafety of the P2P system. The traditional central trustmechanism will not meet the demand of P2P system anymore, so it is necessary toestablish a distributed trust mechanism to enhance the dependability of the P2Psystem.Trust model was the most important parts in trust mechanism. Through thecollecting, transfering and estimating the historical action information of the peer inthe network, the model can normalize and restrict the action by the peer credit value,the reliability of the P2P system is ensured to some content. The users are encouragedto act well in the network by the credit model and the network gets a gooddevelopment.This paper puts forward a comparatively simple distribution model after analysingthe existing trust model. The model evaluates the credit by the method of estimationbased on the credit mechanism of the realistic world. The credits are divided intodirect credit information and recommended credit information after the collecting andanalyzing of the information related to the peers. The reputation value of trade node iscalculated as the proof whether the trade will go on after the correction of the relatedinformation by the different evaluation ability. Simulation tests about the model havemanaged to investigate its performance, and the trust model is feasible and practical.The model has a simple structure and a strong reliability and can improve the usabilityof P2P network. The model needs further study and improvement in the future.