Application Of Trust Model Based On Service Level Agreements In Cloud Resource Access Control

Cloud computing becomes a hot topic because of its superior processing power and broad application prospects. But with the rapid development of cloud computing, there exposes a number of problems, especially cloud security issues. Thus, the security research has profound significance to the development of cloud computing. How to ensure that the cloud service providers offer the high-quality service to users, and to prevent unauthorized users having access to cloud resource is exactly the problem of access control research where concerns. Therefore, to design a trust-based access control model has become the urgent needs of the development of cloud computing.At first, this paper presented cloud security requirements, compared the current typical trust models and summarized the shortcomings in the existing trust model cloud applications. And then it put forward a cloud computing trust model based on service level agreements, introduced the system trust to the model, and gave the calculation method of the value of the trust, working process of the model and trust update process. Finally, combined with this model and attribute-based access control, it proposed a fine-grained access control policy based on trust in cloud environment. A detailed description is as follows:Based on Service Level agreements(SLA, Service Level Agreement), a trust model of cloud computing was proposed. The model is designed to describe the relationship of trust cloud service providers and cloud users objectively and accurately. The two sides agreed to fulfill their interaction according to the negotiated service level agreements. The monitoring module monitors the fulfillment of both sides and gives the appropriate incentives.Indirect trust is calculated combined with the grey system theory and the fuzzy method. Indirect trust includes evaluation of similarity and recommend similarity. This method calculates the evaluation of similarity between entities based on the grey theory, combined with analytic hierarchy process, to describe and update the calculations of dynamic trust model.The paper proposes a fine-grained access control strategy based on the ABAC model and SLA. With credibility as an attribute, this model consists of four tuple is expanded to quintuple, which is better able to apply dynamic and open cloud computing environment, so as to achieve the purpose of fine-grained access control based on trust and to resist all kinds of illegal users' access.