Survey of access control models and technologies for cloud computing.

Access control is an important measure for the protection of information and system resources to prevent illegitimate users from getting access to protected objects and legitimate users from attempting to access the objects in ways that exceed what they are allowed. The restriction placed on access from a subject to an object is determined by the access policy. With the rapid development of cloud computing, cloud security has increasingly become a common concern and should be dealt with seriously. In this paper, we survey access control models and policies in different application scenarios, especially for cloud computing, by following the development of the internet as the main line and by examining different network environments and user requirements. Our focus in the survey is on the relationships among different models and technologies along with the application scenarios as well as the pros and cons of each model. Special attention will be placed on access control for cloud computing, which is reflected in the summaries of the access control models and methods. We also identify some emerging issues of access control and point out some future research directions for cloud computing. [ABSTRACT FROM AUTHOR]