The Role-Based Access Control (RBAC) model is traditionally used to manually assign users to appropriate roles, based on a specific enterprise policy, thereby authorizing them to use the roles' permissions. In environments where the service-providing enterprise has a huge customer base this task becomes formidable. An appealing solution is to automatically assign users to roles. The central con...

We consider the safety problem for Administrative RoleBased Access Control (ARBAC) policies, i.e. detecting whether sequences of administrative actions can result in policies by which a user can acquire permissions that may compromise some security goals. In particular, we are interested in sequences of safety problems generated by modifications (namely, adding/deleting an element to/from the s...

Role-based access control is an important way of limiting the access users have to computing resources. While the basic concepts of role-based access control are now well understood, there is no consensus on the best approach to managing role-based systems. In this paper, we introduce a new model for role-based administration, using the notions of discretionary and mandatory controls. Our model...

We demonstrate how access control models and policies can be represented by using term rewriting systems, and how rewriting may be used for evaluating access requests and for proving properties of an access control policy. We focus on two kinds of access control models: discretionary models, based on access control lists (ACLs), and rolebased access control (RBAC) models. For RBAC models, we sh...

The rapid emergence of GPS enabled devices, sensors and mobile equipment in commercial as well as government organizations has led to considerable research in timeand location-based access control schemes. Location-based access policies enhance the security of an application by restricting access to an object only from specified locations. On the other hand, temporal constraints provide granula...