Analysis And Research Of Trust Model For Peer-to-Peer Network

P2P networks have been becoming one of the indispensable applications in the Internet. However, because of its dynamic, distributed and autonomous properties, peers have a variety of malicious acts, such as unreliable services, a large number of fraud and no contribution to the networks, which lead to lack of trust for the content a peer puts on the network. So how to efficiently manage the trust between peers of P2P networks becomes an important subject in P2P techniques research area. Trust model is the effective method to solve the trust of P2P networks.In order to solve some problems such as no initialization, malicious nodes and the low efficiency in searching the trust path, this paper proposes an improved trust model with reward, punishment and incentive mechanism to deal with trust relationships among nodes in P2P networks, designs the overall the structure of the model and goes deep into the trust initialization, trust calculation, trust path search and trust updating in the trust model. (1) The model adds the trust initialization process. Each node establishes a local direct trust relationship table to manage trust distributedly. (2) The model combines direct trust, recommendation trust and reputation to calculate overall trust value, so that it can calculate the trust relationships among nodes more accurately, and introduces the concept of time decay factor which shows the recent interactions affect the trust relationships between peers more. (3) In the searching of recommendation trust paths, the trust model designs a ACA(ant colony algorithm)-based recommendation trust paths searching algorithm to prevent the joint fraud of malicious nodes, introduces the incentive mechanism to encourage the various nodes'recommendation. (4) In the process of updating trust relationships, it uses reward and punishment mechanism to update trust relationships among nodes and trust values of nodes, this is a good solution to security issues arising from nodes'malicious acts.Finally, this paper analyzes the security of the trust model, studies the rationality of trust computing&updating algorithm and its impact on the direct trust value. The analysis shows that the trust model can effectively solve the malicious nodes problem in P2P networks, and improve the efficiency for searching the trust path.