Delegation of authority is an important process that needs to be captured by any access control model. In role-based access control models, delegation of authority involves delegating roles that a user can assume or the set of permissions that he can acquire, to other users. Several role-based delegation models have been proposed in the literature. However, these models consider delegation in presence of the general hierarchy type. Multiple hierarchy types have been proposed in the context of Generalized Temporal Role-based Access Control (GTRBAC) model, where it has been shown that multiple hierarchy semantics is desirable to express fine-grained access control policies. In this paper, we address role-based delegation schemes in the of hybrid hierarchies and elaborate on fine-grained delegation schemes. In particular, we show that upward delegation, which has been considered as having no practical use, is a desirable feature. Furthermore, we show that accountability must be considered as an important factor during the delegation process. The delegation framework proposed subsumes delegations schemes proposed in earlier rolebased delegation models and provide much more fine-grained control of delegation semantics.
In addition, GTRBAC has recently adopted role-based delegation notions with hybrid hierarchies and multiple hierarchy semantics to support fine-grained delegation schemes REF .
Fine-grained role-based delegation in presence of the hybrid role hierarchy
SACMAT '06
Computer Science