Research On Routing Algorithms And Related Security Technologies Of Structured P2P Overlay Networks

Peer-to-Peer overlay network, which is self-organized and distributed, can make full use of the edge system entities in Internet-scale to construct large-scale cooperating and resource sharing environments. With fast development in recent years, the p2p technology is used widely in many application areas like file sharing, search engine, distributed storage, distributed computing and etc. The p2p network can be classified into unstructured p2p and structured p2p in terms of the topology, and the structured p2p network is the third generation p2p network and more popular used, while the unstructured p2p is the first and second generation.As the network scale increasing continuously, the structured p2p network requests more efficient routing performance, while the traditional structured p2p routing protocols using O (logn) routing fingers to get O (logn) routing path and spending O (logn) network churning. In order to improve the routing algorithm efficiency of the structured peer-to-peer overlay networks, using much less routing fingers to get longer routing path and reducing the network churning, the routing algorithms are studied hotly. Because of the openness, reciprocity, random and spontaneous joining of the nodes and the lack of centralized system management in the structured distributed p2p system, some urgent problems regarding the availability and security of p2p network remain to be solved, such as evil node attacking, team evils cheating, intellectual property rights in p2p and etc. This paper presents in-depth study on p2p routing algorithms and p2p security technologies for structured p2p network, and makes some creative research results as follows:(1) Presented a new routing algorithm of structured p2p overlay networks, called CSSP. This routing algorithm use single-circle topology with cache nodes, successor nodes and a super node. The CSSP can get O (N) routing path only use O (L+2) routing fingers, and the routing operations can finished in O (2) hops. Cache policy, routing maintenance algorithms for nodes’ joining and leaving and election algorithms for super node were presented to ensure the self-organization. Simulations and analysis showed that the CSSP is an efficient route algorithm with quickly routing speed, lower churning count and high fault-tolerance.(2) Presented a new routing algorithm K-CSSP of structured p2p overlay networks based on clustering the nodes’communication history. This routing algorithm computing the nodes’stability via storing the nodes’communication history distributed. The K-CSSP uses the K-means algorithm to cluster the CSSP nodes by the stabilities into K regions which inter-linked each other by steady kernel node, and it can get O (N) routing path only use O (L+K) routing fingers, and the routing operations can finished in O (K) hops. A distributed cluster model, routing maintenance algorithms for nodes’ joining and leaving and cluster-center node’s updating algorithm were presented to ensure the self-organization. Simulations and analysis prove the rightness and efficiency with fast cluster constringency, steady routing performance and topology.(3) Presented a new distributed p2p trust model NBRTrust. Constructed the distributed local trust degree appraising networkβ-list based on the distributed storage for the nodes’communication history, the NBRTrust trust model, which was proposed to quantify and evaluate the trustworthiness of nodes, was formed by global trust model with nodes’correlative similarity weighted which was distributed computed from theβ-list. A mathematical description and a distributed implementation were defined, and a p2p communication model based on the NBRTrust model was designed. Simulations and analysis proved the NBRTrust was more impersonality comparing with traditional local trust model and global trust model, and it can withstand simple evil node’s attacking and team evil nodes’cheating also. The NBRTrust is an efficient global trust model.(4) Presented a new content controlling method HFFCSC based on biometric for structured p2p overlay networks. The HFFCSC generated 256 bits key and 256 bits IV sequence by obtaining the user’s human-face feature to encrypting and decrypting the p2p content. A p2p response message was designed which including user’s human-face parameter, to control the copyright of shared files. Experiment and analysis prove the rightness, and the HFFCSC is a valid content controlling method for structured p2p overlay networks.