Temporal Role Hierarchies

Information security and access control is an important part of CSCD applying. RBAC (role based access control) as an access control technology using for distributed system has been widely researched these years. Role hierarchies is one component of RBAC model, it can reduce the workload of permission assignment. Nowadays most research of RBAC has no relation with timing constraint. The main purpose of this article is to study the effect of temporal constraint acting on role hierarchy. The basis of the study is RBAC96 model, first we analyse the change of role state, propose 3 forms of temporal constraint and give the expression of temporal constraint. Then we present an analysis of the effects of temporal constraint on role enabling and role activation which has various implication on a role hierarchy, and at last we formally describe a timing restricted role hierarchies model