The Research And Design Of P2P Anonymous Communication System

In recent years,with the widespread use of Internet,P2P network technology appears in file sharing,video multicast,instant messaging and other fields.The distributed structure of P2P made it good expansibility and flexibility,but its open,anonymous and self-organized characteristics has also offered a path for the spreading of virus and junk data,the security has aroused people's common concern.Therefore,the security of P2P network become very important.Aiming at the above problems,this thesis applied more extensive research on the existing anonymous communication technology and P2P network trust model,this thesis launched following a series of work:1)Applying the theory of Cluster to the P2P anonymous communication system,this thesis proposes a node selection strategy to improve the anonymity of the network.This scheme uses a method of Cluster statement and adopts a limited strategy of node selection,which avoids using multiple nodes from the same cluster in the same circuit to improve the anonymity of P2P system.The experimental results indicate that when the number of Cluster is more(but not too much)in system,the entropy of the systemis greater,and when the number of Cluster is divided into half of the number of all nodes,the entropy is the greatest,that is the anonymity is the best.We show the feasibility and accuracy of our approach by theoretical analysis and validate experiment.2)In terms of the problem of basic ant colony algorithm and traditional network trust model that is easy to lead to local optimum and has bad trust degree of nodes,this thesis presents an improved ant colony algorithm,and based on the theory of Cluster,this thesis designs a new P2P network trust model(TMPCACA).In this model,the proxy server is looking for the most trusted and the best server node in the network by the methods of path selection and pheromone updating,and the measure for the quality of the path.The experimental results indicate that the trust degree of TMPCACA is more than 0.9 in the static network and dynamic network environment and can also be maintained at more than 0.8 in the oscillating network environment.It shows that the model has a great advantage and effect on solving the problems of trust degree of nodes and network dynamic of the existing P2P network trust model.