A Trust and Unauthorized Operation Based RBAC (TUORBAC) Model

This paper introduces trust and unauthorized operation to traditional RBAC model, and proposes a trust and unauthorized operation based RBAC model (TUORBAC model). The model has greatly improved in safety compared to traditional RBAC model. Before user activates the roles, TUORBAC model downgrade the roles of user according to the average severity of user historical unauthorized operation. When the average severity of user historical unauthorized operation is high, we directly downgrade roles of user to the lowest. Otherwise, we calculate the value of trust, and downgrade the roles of user according to the value of trust, finally activate downgrade roles. In addition, the model introduces downgrade roles, which stored downgrade roles of user. If downgrade roles are nonempty, we directly activate downgrade roles without re-judged, which improves the efficiency of the system.