Modified hierarchical privacy-aware role based access control model

Privacy-aware role based access control (PRBAC) model extends much appreciated RBAC model and it is one of the leading models to define privacy policies and their enforcement. PRBAC extension, to hierarchical PRBAC (H-PRBAC), can express most of the privacy policies. But the limitation in H-PRBAC's Purpose hierarchy can lead to the explosion of policy assignments. In this paper, we review and provide an enhancement needed in the H-PRBAC model to overcome these limitations. Another limitation of PRBAC model is the lack of condition redundancy checking required for the assignment of new policies. In this paper, we provide an algorithm that was much needed for this purpose and review its complexity.