A Role-Based Dynamic Authorization Model and Its Implementation in PMI

The efficient authorization is the precondition of implementing access control. Traditional access control technology which lacks dynamic authorization mechanism focuses on the beforehand authorization process. Based on usage control (UCON) which is new access control technology, this paper proposes a role-based dynamic authorization model. This model extends RBAC by introducing elements of UCON such as conditions, obligations and attributes of subjects and objects. A formalized description of the model is given and its application in PMI is also discussed. The model can efficiently solve the problems caused by dynamic authorization.