Formal authorization approaches for permission-role assignments using relational algebra operations

Abstract

In this paper, we develop formal authorization allocation algorithms for permission-role assignments. The formal approaches are based on relational structure, and relational algebra and operations. The process of permission-role assignments is an important issue in role-based access control (RBAC) as it may modify the authorization level or imply high-level confidential information to be derived when roles are changed and request different permissions. There are two types of problems that may arise in permission-role assignments. One is related to authorization granting process. Conflicting permissions may be granted to a role, and as a result, users with the role may have or derive a high level of authority. Another is related to authorization revocation. When a permission is revoked from a role, the role may still have the permission from other roles. To solve the problems, this paper presents an authorization granting algorithm, and weak revocation and strong revocation algorithms that are based on relational algebra operations. The algorithms can be used to check conflicts and therefore to help allocate permissions without compromising the security in RBAC. We describe how to use the new algorithms with an anonymity scalable payment scheme. Finally, comparisons with other related work are discussed.