综合基于角色的访问控制和信任管理各自的优势,提出了一个适用于开放式环境的细粒度可控委托授权模型——FCDAM(fine-grained controllable delegation authorization model),基于信任度实现了对角色中具有不同敏感度的权限传播控制.提出了为本地策略中的权限分配信任度阈值的方法,为RT0添加了信任度支持,给出了在这种扩展后的信任管理系统中计算实体信任度的算法,并结合具体实例对模型的使用进行了说明.
A fine-grained controllable delegation authorization model (FCDAM) suitable for open environments is presented. It integrates the merits of both RBAC (role based access control) and role-based trust management and can effectively control the propagation of permissions of different sensitivity levels in roles. An approach for assigning trustworthiness thresholds to permissions in local access control policy is discussed. The RTo framework is extended to support trustworthiness and the algorithm of calculating the values of trustworthiness of entities in the extended framework is proposed. The usage of the FCDAM model is illustrated through a typical example.