基于角色和任务的CSCW系统访问控制技术研究

针对现有方法不能很好地满足CSCW系统对访问控制的需求,提出基于角色和任务的CSCW系统访问控制模型RTBAC(Role and Task-Based Access Model).该模型形式化地描述了用户、角色、任务、权限、工作流等要素及其相互间的关系,通过分配和取消角色来完成对用户权限的授予和取消,并提供了角色间偏序继承和指派关系定义,通过引入任务概念、任务类型划分及角色和任务之间的关系定义,实现了依据任务和任务状态不同对权限进行动态管理.该模型是针对CSCW系统多用户、动态、协作等特性提出的,能较好地满足CSCW系统对访问控制的需求.

Study of the Role and Task-based Access Control Technology for CSCW System

CSCW systems have many new requirements for access control,which cannot be met by existing models. In this paper,a new role and task-based access model (RTI3AC) was presented to meet these requirements. This model formally describes the relationship between the key elements of access control such as user, role, task, privilege, and workflow. The model grants and revokes access privileges of users by assigning them roles and canceling their roles, and provides partial inheritance and delegation between roles. In this model the conception to task was introduced, group tasks were divided into workflow task and independence task, and the relationship between roles and tasks was described. From those the model can dynamically manage the permissions through tasks and tasks' status. RTI3AC model is brought forward aiming at accommodating with the characteristics of collaborative systems such as multi user, dynamic, and collaboration. It can meet the requirements for access control in CSCW system adequately.