Classification and formulation of role-based separation of duty constraints

Separation of Duty (SOD) is a fundamental principle in security systems and has a long history in computer security research. It is also an important characteristic in the Role-Based Access Control (RBAC) system. Various categories of this principle have been pointed out for RBAC environment by different researchers, but they have neither been classified nor formulated. This paper beside classifying and formulating all the former introduced types of SOD in Role-based environment; presents and defines formally new types of Role-based SOD