The central notion of Role-Based Access Control (RBAC) is that users do not have discretionary access to enterprise objects. Instead, access permissions are administratively associated with roles, and users are administratively made members of appropriate roles. This idea greatly simplifies management of authorization while providing an opportunity for great flexibility in specifying and enforcing enterprise- specific protection policies. Users can be made members of roles as determined by their responsibilities and qualifications and can be easily reassigned from one role to another without modifying the underlying access structure. Roles can be granted new permissions as new applications and actions are incorporated, and permissions can be revoked from roles as needed.