A Task-and-Role-Based Access Control Model for Workflow System

An access control model called T&RBAC (task-and-role-based access control) is proposed, which based on RBAC and TBAC and models from the tasks in workflow and dynamically manages the permissions through tasks instances and task context. In the, T&RBAC model, permissions are assigned to tasks, tasks are assigned to role, and the relationships between tasks and task instances are defined. The basic concepts of T&RBAC are explained, the formalization descriptions are given, the related methods which use task context to dynamically control security permission are be put forward, and the strategies used to assign users to role are established. At last, the supported security principles are be analyzed.