Research And Trust Improvement For Chord Protocol In P2P Networks

With the fast development of computer network technology, Peer-to-Peer (P2P) network, as a distributed computing architecture, also develops rapidly. However, P2P technology brings us not only more chances but also some challenges. It is because malicious nodes exist in the P2P network and lead to a variety of aggressive behavior becomes a threat in the normal network.Chord and other DHT (Distribute Hash Table) protocol, as a new generation of the underlying routing protocols of structured P2P networks, has brought new development for P2P networks. However, in an insecure network, due to the presence of malicious nodes, there are also some security issues in the chord routing process:the security of the routing table, routing truncation attack, incorrect routing forwarding and routing conspiracy to deceive.Because in the Chord network, the implementation of the work of routing was originally the node itself, P2P trust mechanism is also applicable to the work of routing between nodes. This thesis designs a trust mechanism based on the Chord routing, and applies this trust mechanism to the process of routing forwarding between nodes.In the process of trusted routing, routing between nodes is based on the trust mechanism of the real world, using the way of quantitative to assess the trust. Moreover, trust will be divided into subjective and objective, and a comprehensive trust value will be created as a route to forward decision-making. Through simulation experiments the performance of the trust mechanism have been studied and demonstrated that in the non-secure network environment, this model can reduce the Chord routing lookup failure rates. However, there are also inadequate, and more research and improvement need to do in the future.