Analyse And Design Of Trust Model In The Peer-To-Pee Network

P2P which is based on the distributed technology, broke the traditional Client/Server model. Each node in a P2P network has similar functionalities and plays the role of a server and a client at the same time, make full use of the resources on the edge of networks. Peers in the P2P networks have a full share of the information, processor, memory and cache through direct connection but not dependent on the supports of the centralized server, which make the P2P network has the advantages of high resource utilization, strong expansion capability, good network performance, high speed of information flowing and powerful searching capacity. These made the P2P technology has a widely used in the distributed computing, searching, file exchange, team working and other fields. Related researches in the P2P field gradually carried out with the continuous expanding application of the P2P technology. At present, research of the P2P focus on these three aspects:Construction of the Topology of P2P Overlay, resource searching and location in the P2P network and security of the P2P System.The main research of this thesis is on the trust management of the P2P network and the construction of the P2P overlay topology.Firstly in this thesis, combined with characteristics of the P2P networks and analyzed feature of the trust relationship between P2P nodes, made the definition of trust and reputation in the P2P network according to related research findings of trust and reputation in the sociology, economics and other subjects. Then we made a study of the existing P2P trust models, contrastive analysis the advantage and shortage of these models. Secondly, considered the P2P networks have the characteristics of no central, self-organization, dynamic changes of topology as well as the nodes'interoperability, using the Small World theory exits in the human society and in the computer networks, we propose a layered P2P network trust management mechanisms which is based on the nodes' global reputation. According to the layered P2P network trust management thinking described in this thesis, we make full use of the distributed and the self-organization features of the P2P network to elect the nodes who had higher global reputation to play the role of reputation guarantees of the other nodes and to manage their information of reputation. This layered P2P network trust management mechanisms enhances the security of the whole P2P system, reduces the transmission load brings from the trust information querying and updating, improves the ability of anti-attack by punishing the malicious acts or malicious recommend of the nodes.Based on the layer management proposed in this thesis we design the achievement mode of the layered P2P network trust management mechanisms we proposed using the DHT routing protocol, Kademlia. The achievement mode includes the aspects of the storage, query and update of the nodes'trust information and reliable interactive process between nodes.Finally we described the trust evaluation model of our P2P network. In this model, we take some punitive action on the nodes who have the malicious acts which controlled and isolated the these actions effectively. On the other hand, considering the heterogeneous of the nodes we give the higher trust value to the nodes who have longer online time and more contribution to the network, gives full play of processing capacity of these nodes.