Hybrid role hierarchy for the extended role based access control model

Role based access control (RBAC) has emerged as a leading access control model to other traditional access control models. However, the traditional RBAC models can not capture fine-grained authorization with mono-type inheritance. In this paper, we discuss the hybrid inheritance based on our extended RBAC model, which is very desirable for capturing the fine-grained access control permissions. When the hybrid inheritances coexist in a role hierarchy, inferring such indirect relations between a pair of roles can became very complex. In particular, we study how the new inheritance relations between roles that are indirectly related can be easily derived through the inference rules, which provides a basis for formally analyzing the hybrid inheritances.