Abstract
Role-Based Access Control (RBAC) is the most widely used model for advanced access control deployed in diverse enterprises of all sizes. RBAC critically depends on defining roles, which are a functional intermediate between users and permissions. Thus, for RBAC to be effective, an appropriate set of roles needs to be identified. Since many organizations already have user-permission assignments defined in some form, it makes sense to identify roles from this existing information. This process, known as role mining, is one of the critical steps for successful RBAC adoption in any enterprise. In recent years, numerous role mining techniques have been developed, which take into account the characteristics of the core RBAC model, as well as its various extended features. In this article, we comprehensively study and classify the basic problem of role mining along with its several variants and the corresponding solution strategies. Categorization is done on the basis of the nature of the target RBAC system, the objective of role mining, and the type of solution. We then discuss the limitations of existing work and identify new areas of research that can lead to further enrichment of this field.