基于信任约束的用户安全管理

在开放的网格环境中，用户行为的动态性和不确定性，使得现有的基于证书的静态用户管理难以及时地将用户的恶意行为进行标识并对用户后续行为进行控制。针对该问题，提出一种基于信任约束的用户安全管理方法。该方法基于对用户信任计算的结果，根据用户信任等级的变化，建立用户信任黑名单和白名单；并基于用户信任等级与资产价值之间的关系，建立一种信任策略。实验结果表明，该方法建立的用户信任黑名单、白名单和信任策略，作为访问控制机制的一种动态信任约束，加强了对系统授权的约束，使得用户能够获得的访问能力与其历史行为相关联，加强了对用户行为的控制，提高系统安全。

User security management based on trust constraint

It is very difficult to identify the malicious acts of users and to control the future acts of users for the existing static certificate-based user management in an open grid environment because of the dynamics and uncertainty of user behavior. To address the problem, a method for user security management based on trust constraints was proposed. In this method, according to the result of trust computation, the trust black-list and white-list were established by monitoring the change of trust level of users, and trust policies that stated the relationship between user trust and asset value were set. The testing results show that, as a dynamic trust constraint of access control mechanism, the trust black-list, white-list and trust policies strengthen the constraints on the system authorization, and effectively control the user behaviors by associating user's capacity accessing to resources with his or her history behaviors, which improves system security.