On the Complexity of Authorization of Temporal RBAC in Cloud Computing Service

Cloud computing provides a powerful environment for growing a variety of services and data. Role-Based Access Control (RBAC) has widely been accepted as a promising model to capture dynamic requirements in cloud computing service. Constraints are a powerful mechanism for enforce higher-level organizational policy for RBAC. In this paper, we study temporal constraints and role-based constraints, and propose Temporal Constraint Consistency Problem (TCCP). We study the computational complexities of TCCP in different subcases and generate a valid assignment to satisfy all the constraints, then reduce them into general P, NP and NP-Hard problems. By this way, we can provide a possible solution to the conflicting constraints which may coexist in a cloud computing environment.