The Research Of Reputation System Under The Environment Of Peer-to-Peer Networks

The anonymity and dynamic characters of Peer-to-Peer (P2P) system makes it an ideal medium for selfish and vicious action. In order to solve this problem, Peer-to-Peer reputation systems are proposed to evaluate the trustworthiness of peers and to prevent the selfish, dishonest, and malicious peers' behaviors, which collects local reputation scores and aggregates them into the global reputation. In this paper we propose a DHT trust overlay network (DHTON) to model the network structure and the storage of reputation information. We also design a robust and distributing reputation system, DHTrust, which takes full advantage of the Distributed Hash Table (DHT) to distribute local reputation to trade off the damage of fake reputation information by genuine reputation information. By using the trust evaluation towards two reputation scores, we can also distinguish and evaluate the fundamental behaviors of peers in Peer-to-Peer network, i.e., providing service and issuing reputation scores. For the reason of adaptability to the dynamic character of Peer-to-Peer network, we take dynamic node mechanism into account, which helps the system insures convergence effectiveness and robustness when there are nodes enter or leave the system. Finally, we upgrade our system by classify the services and requests of nodes, and label the node, so that the system can query the resources rapidly. The dynamic mechanism and services and requests classification mechanism make our system much more in conformity with the reality of Peer-to-Peer system. Through the simulation experiments, we find our system makes significant performance gains in convergence speed and aggregation accuracy, and the most important, is robust to malicious peers.