Role based access control models

Since the 1970s, computer systems have featured multiple applications and served multiple users, leading to heightened awareness of data security issues. System administrators and software developers focused on different kinds of access control to ensure that only authorized users were given access to certain data or resources. One kind of access control that emerged is role-based access control (RBAC). A role is chiefly a semantic construct forming the basis of access control policy. With RBAC, system administrators create roles according to the job functions performed in a company or organization, grant permissions (access authorization) to those roles, and then assign users to the roles on the basis of their specific job responsibilities and qualifications. A role can represent specific task competency, such as that of a physician or a pharmacist. Or it can embody the authority and responsibility of, say, a project supervisor. Roles define both the specific individuals allowed to access resources and the extent to which resources are accessed. For example, an operator role might access all computer resources but not change access permissions; a security officer role might change permissions but have no access to resources; and an auditor role might access only audit trails. Roles are used for system administration in such network operating systems as Novell's NetWare and Microsoft's Windows NT. This article explains why RBAC is receiving renewed attention as a method of security administration and review, describes a framework of four reference models the authors have developed to better understand RBAC and categorize different implementations, and discusses the use of RBAC to manage itself. The authors' framework separates the administration of RBAC from its access control functions.