Controllable authorization delegation model supported by constraints

Trust management is a common approach on access control in the distributed environment. RT is one of the frameworks for role-based trust management. However, RT has some faults, and one of the main faults is the delegation control. To address this problem, this paper proposes a controllable authorization delegation model supported by constraint. First, the framework of RT and a reasonable classification of the RT attributes are introduced. Second, to better control the spread of permission, the constraint on the authorization source is implemented and the formalization of constraints is described. Finally, a usage of the model is illustrated through a typical example.