Research On Feedback-based Distributed Trust Model In P2P Networks

In the recent years, P2P network becomes one of research hot topics and anattention focal point in industry, which widely using in collaborative computing,distributed storage, file sharing and other fields. However, the essentialcharacteristics of the P2P network such as openness, anonymity and autonomy haveprovided the favorable conditions for making a lot of malicious behavior existingcurrent networks, such as joint defrauding and forging documents, which impact theavailability and service quality of the P2P network. To solve such problems, the majorideas so far focus on trust and reputation mechanism research. Trust mechanismevaluates the history behavior of the users to predict the future behavior of the usersand support other users making the right choice to resist malicious attacks andundesirable behavior.Trust model is a key component of trust mechanism, we can constructquantitative evaluation system through trust model to measure the trust credibilityvalue of the node. Although the trust model can reduce the impact of maliciousbehavior in P2P network effectively, but the existing trust models have fragile point,so there are a lot of attacks to trust model in P2P networks.In this paper, we study several existing classic trust model and analysis existingmalicious attacks in current networks, find out that the lack of resisting maliciousattacks about existing trust model and point out the design of the trust model shouldfully consider all sorts of malicious attacks. The main contributions of this paper areas follows:An effective feedback-based dynamic trust model named EFTrust is proposed inthis paper. The model can improve the effective aggregate capacity of evaluating thetrust information by using feedback credibility to filter the dishonest feedback. Byintroducing a mechanism based on sliding time windows to enhance the dynamicadapting ability, the model can adjust the trust value of the nodes dynamicallyaccording to the change of node’s behavior. Theoretical analysis and experimentsshow that the model can resist the malicious attacks effectively.Using the DHT-based Chord protocol we implement distributed storage andquery of trust data. The placement problem of the global credibility can be solved Byintroducing the trust value node management scheme. Then we analysis the distributed scheme theoretically that can ensure trust data storage security. Based onabove scheme, we give the overall framework of the trust management system bydescribing the entire process of the trust model, and propose a distributed algorithm toimplement EFTrust model.Combining above proposed schemes in the dissertation, a P2P file sharingsimulator systems is designed and implemented by JAVA program language, wecompare the several other classical trust algorithms and EFTrust algorithm throughthe simulator system. The simulation experiments show that show that our proposedalgorithm outperforms the other model with more predicting capabilities accurately,better dynamic adaptability and self-control ability, can inhibit the swing strategiesand collusion attacks of the malicious nodes effectively.