Research And Implement On The Technology And Theories Of Access Controls

With the rapid development of information and technology, database faces more serious security situation. Research in the access controls has been an important part of the area of the database. In this paper, we not only discuss the theories of access controls in details, but also give the detailed discussions for implementing MRBAC, the access control mechanism for NHSDB, a secure DBMS prototype. Firstly, in this paper, we review traditional access controls and analysis shortcomings of them. And then, the paper summaries disadvantages of traditional access controls and introduces modern access control---usage control. In order to solve the problems that usage of a digital object can be not only time-constrained, but also temporal and privilege-consuming, in recent information systems.,we present a new access control model—A Times-based Limited Access control Model. This model defines the maximum times that privileges can be exercised. When the times of privileges is consumed to zero or the period of authorizations is expired, the privilege exercised on objects will be automatically revoked by the system. This model protects system resources from being abused to a certain extent and alleviates the burden of system administrators. Based on what we discuss, we give an initial discussion for mutability attributes in the UCON. At the same time, we introduce the implement for MRBAC, the access control mechanism for NHSDB, a secure DBMS prototype. Finally, we draw a conlusion for this paper and future direction in this field is discussed.