P2p Shared-storage System Security And Its Client To Achieve

In the past few years, P2P network has grown rapidly with the development of internet. As an important branch of P2P application, content distribution technology can take advantage of vast idle network space and overcome the bottleneck of traditional C/S model. Making the best of terminal computer in internet to cooperate with each other, the share, query, fetch, acquirement and storage of huge information can be easily realized. However, due to the self-autonomy and high dynamic of P2P network, all of nodes in P2P network can join or quit randomly, it is hard to guarantee the security of anonymous information exchange. To improve the system security, this paper has researched the accessing control technology of content distribution in P2P network.According to the special requirement of distributed storage in special circumstances, this article introduces a secure P2P Storage Sharing System. It focuses on the realization of the client end of the system. The article introduces a two-level P2P network structure through an improvement of the hybrid P2P network structure. In the new structure, there are two tiers that form a hybrid P2P network, high-tier nodes manage low-tier nodes. The high-tier nodes communicate by Gnutella protocol and the low-tier nodes use BitTorrent Protocol. As a result, the system can provide both C/S and BT as down loading methods, which resolves the bottleneck problem of C/S down loading method in a storage system and improves the system performance and down loading effiency.After analysing the actual security requirementof the distributed storage system, the system design is considered from three aspects: Confidentiality, Integrity, usability. On the basis of all existed access control technologies, combining the features of P2P networks and the actual requirement of the current P2P storage sharing system, this article did a research on the secure strategy model BLP(Bell-LaPadula). Moreover, on this basis, it designs a satisfied access model according to the level-based access control model, which ensures the system confidentiality in the information stream.Moveover, in order to satisfy the high security requirement of the system, the article designs a simple one-way node authentication protocol; improves the file storage process, in which the file is not save as a whole, but stored as balanced file fragments in each node of the network. This realizes the real distributed secure storage.