Management of access privileges for dynamic access control

Access control is an important security mechanism for the protection of sensitive information and critical system resources. While it has been well-known that traditional access control models (TACMs), such as DAC, MAC, RBAC, etc., are not well suited for open networks due to the lack of dynamism in the management of access privileges, pro-active or dynamic access control models (PACMs) developed in recent years generally suffer from performance problems due to complex evaluation performed prior to access authorization. In game theory based dynamic access control models, which are one type of dynamic models, each access is modeled as a game that is played between the accessing subject and the accessed or protected object and the result of the play serves as the basis for making the authorization decision. Thus, delay is unavoidably introduced into the authorization process due to such pre-access evaluation. To overcome the shortcomings of TACMs and PACMs simultaneously, in this paper, we propose a new access control model called ISAC that, unlike all present access control models, is used not as a mechanism for access authorization but one for dynamic management of access privileges upon the completion of each access with the result being an updated set of access privileges for the accessing subject and used for updating the corresponding access control list for the subject. Access authorization will still be performed in the same way as that in the traditional access control models. Thus, ISAC offers the advantages of both traditional access control models in performance and pro-active access control models in dynamism. We will apply incomplete information static game to the development of ISAC in which we will show that there exists at least one Bayesian Nash equilibrium for the game play, which is the theoretical foundation for ISAC. We will also describe a framework design and an example implementation to illustrate the application of ISAC to access control. At last, we will present some experimental results to show that while maintaining the effectiveness of dynamic access control through the management of access privileges, ISAC can achieve the performance of traditional access control models.