Research On Dynamic Access Control Technology Based On Trust And Role In Cloud Computing Environment

As a new information service mode, Cloud computing put the distributed storage, software and other resources together, and provide services to users through internet. This kind of service mode has greatly improved the utilization of computing resources, and significantly reduce operating costs and improve operational efficiency, it contributes users to use computing resources and acquire network services more efficient and convenient. However, users face security, privacy and other risks when they use cloud services, for the cloud environment has openness, complexity and other features, result in their doubt about the reliability of cloud computing, and the development of the cloud computing has been suspended. Therefore, secure access to cloud computing has become a major research direction.As an important measure to control users access to service and sharing data with others, access control technology plays an important role in ensuring the security of cloud environment. Therefore, this paper has deeply studied on the access control in cloud environment, and the mainly work is concluded as follows:1. Make sure the cloud is security from the aspect of cloud server. Users would have security problem if the node provides malicious service, and it will influence their trust to the service provider, so it is necessary to evaluate the trust of service nodes. This paper use direct trust, indirect trust and comprehensive trust method to calculate the trust value of service node, in order to make trust value more authenticity, improve the reliability of the trust evaluation of the service node, and ensure safety access of authorized users, we proposed add punishment and reward function, time decay function and limit the maximum historical interaction record in the calculation.2. Make sure the cloud is security from client based on access control. If the user's request is malicious or mendacious, it would not only result in the cloud can't provide normal service but also result in the cloud resource occupied and even destroyed, this paper add privilege level concept, it can adjust user access according to user behavior, and user behavior should verified by evaluate the trust of user behavior to determine whether the user is reliable, in order to improve the accuracy of the trust evaluation, so proposed use the triangular fuzzy number.to improve the traditional ANP method, and ensure the security of the user.3. Finally, improve RBAC by ensuring the user and server that in the cloud environment is reliable, so that the access control model can dynamically adjust users' access permission according to the user behavior, select optimal node to response a user request according to the credibility of the service node, make sure the security of both parties and construct a dynamic access control model which can adapt to the environment and characteristics of cloud computing.