Research On Trust-Based Dynamic Access Control In Grid

Grid security is the essential mechanism in grid computing systems. Grid system consists of various resources, and the resources have some features of dynamic change, geographical dispersion and heterogeneous systems, which make the security issues of the grid system much more complex than the network. When grid systems are widely applied in the national defense, commerce, medical service and so on, more huge and complex information resource needs to be managed and controlled, but the traditional access control model can't fulfill such system demand.In order to solve the security issues incurred by the dynamic and uncertainty of grid environment, we introduce the trust mechanism into the access control. When entities can't be identified, grid systems can directly use their trust to implement the access control regardless of their identities.The trust evaluation model in the grid system is used to initialize the trust relation of the entities, compute and update their trust. After comparing synthetically and analyzing thoroughly the current trust model, we present the GTEM model to compute and update the trust of entities in grid environment, which inherits their advantages and rejects their disadvantages.Then we analyze the classical access control model BLP, present its advantages and disadvantages, and give the improved opinions. Based on these opinions, we propose the access control model TLBAC, and give the element definition and the rules of operation.Finally through the synthesis application of the GTEM model and the TLBAC model, we establish one kind of the access control frame based on trust, and analyze the function of various components in this frame.