Abstract
The last two decades have witnessed an emergence of role-based access control (RBAC) as the de facto standard for access control. However, for organisations already having a deployed RBAC system, in many cases it may become necessary to associate a temporal dimension with the existing access control policies due to changing organisational requirements. In such cases, migration from RBAC to a temporal extension of RBAC becomes essential. Temporal RBAC (TRBAC) is one such RBAC extension. The process of creating a set of roles for implementing a TRBAC system is known as temporal role mining. Existing temporal role mining approaches typically assume that TRBAC is being deployed from scratch and do not consider it as a migration from an existing RBAC policy. In this study, the authors propose two temporal role mining approaches that enable migration from RBAC to TRBAC. These approaches make use of conventional (non-temporal) role mining algorithms. Apart from aiding the migration process, deriving the roles in this manner allows the flexibility of minimising any desired role mining metric. They experimentally evaluate the performance of both of the proposed approaches and show that they are both efficient and effective.