Research On The Immune Strategy For Polluted File Propagation In Structured P2P Networks

Nowadays, Peer-to-Peer(P2P) network which makes a great impact on the development trend of the Internet generation has become one of the main application in current Internet for showing the unique advantages of cooperative work, streaming media services, distributed resource sharing, large-scale parallel computing, etc.However, it is precisely because the characteristics of P2P system such as distribution, openness and autonomy, etc, that it has to face the enormous security challenges, and file pollution in P2P file sharing system is a prominent problem of these.In this paper, the main current DHT network and security issues of file sharing system are deeply discussed. To deal with the file pollution problem in structured P2P file sharing systems, an anti-pollution strategy based on the combination of file propagation chain tracing and immune controlling is proposed.First,a file propagation chain tracing system is proposed witch is take Chord as its base of network, with the common characteristics of DHT network and role of various types of nodes in the process of file sharing. With this system, the details of location of storage and spread path of each file for share can be recorded in the process of file sharing. Thus, it lays the foundation for anti-pollution. Second, a biological immune model is established with the characteristics of structured P2P network on the basis of the file propagation-chain tracing system. And then the mechanisms for alarms collection from the nodes that detect polluted resource, propagation-chain tracing to locate all the suspicious files and nodes,immune response and antibodies memorizing witch used to check the authenticity and validity of new files for sharing when node upload it are designed, with which an immune strategy is proposed which can not only eliminate the polluted clusters and indexes effectively but also prevent the reviving of the old pollutions.Meanwhile, the permissions of the nodes used to constrain the ability to access the services are estimated according to the result of the immune response.The experimental results show that this strategy can curb the propagation of polluted files effectively and quickly even in the severely polluted structured P2P networks.