A Research On Trust Based Access Control In P2p Network

P2P is called peer to peer technology, it's an active research topic in recent years. P2P technology achieves cooperative computing and resource sharing according to making full use of all the peers that attend the network. The equivalent nodes in the network can communicate and share resource directly without the third party, based on the advantage, the application of P2P technology develops rapidly. Because the P2P network does not have a center and is autonomous, the security problem of P2P network is especially serious; it has been the main causation to restrict the next step development of P2P technology. Therefore, how to solve the security problems in P2P network is a new research hotspot.Present researches mainly focus on offering security protection to the service asker using trust scheme, lack the protection to the service providers; Traditional access control technology only provides protections to the service providers, it is not suit to the P2P network. Aimed at security problems in the P2P network, this article analyzes the shortages of P2P trust model and access control, proposes a fine-grained trust model based on grey relation (GM_TRUST), and make a deep research on the access control based on trust, main work is as follows:(1) The present peer-to-peer trust models are too coarse and lack enough ability of synthesizing the feedback.This article presents a new fine-grained trust model for P2P network based on grey relation. The peers are divided into different regions according to interest and speciality and the direct trust is gained by colligating the evaluate for all attributes of one service. A memory factor is introduced to describe the characteristic that trust trail off along with time. The grey relation is used to measure the accurateness of feedback. Analysis and experiments show that compared with existent models, the proposed model evaluates peer's trust value more accurately and it has better capability to resist the attack by the dynamic malice peers and peer's dishonest feedback.(2) In the interest of solving service providers'security problems, design a P2P access control scheme based on trust (THBAC), which contains two departments:resource access control scheme (RACS) and domain member management scheme (DMMS). RACS is the access control to resource of the member in the domain, we combine the thinking of the BLP and HBAC models, take the asker entity's trust degree as a factor of access authorization, it shows the dynamic, and consider the network environment.(3) DMMS is proposed on base of weighted secret sharing scheme. Several peers joining up can implement management to domain members as long as the sum of their weights reaches the threshold value. Enhance the agility and security of access control, fit the P2P network's security better.(4) Design a access control module based on trust by integrating GM_TRUST trust model and THBAC access control scheme, and describe its functions and critical module, at last analyze the capability of the module according to simulation and experiments.Research in this article combines the trust model and access control closely, resolves the security problems of service askers and service provides in the process that the nodes in P2P network communicate with each other.