A new role-to-role delegation model

Role-based access control (RBAC) model is recognized as an efficient access control model for large organizations. PBDM2 is a role-based delegation which is built on RBAC. But in many cases, not all the roles of a user can delegate to others and not every user can accept the delegation. To tackle this problem, this paper proposes a new role-to-role delegation model. The new model is based on RBAC 96 model and PBDM2 with some improvement. We divide roles into three layers and define some constrains to limit arbitrary delegation. Then we represent the model formally and use semaphore primitive to describe the mechanism of delegation and revocation. Finally the algorithm of this role-to-role delegation model is given. The delegation becomes safer in new model.