Abstract: Dynamic environments pose new challenges to access control. In order to guarantee the security of information system in dynamic environment, the needs for realtime update of access control policies rise while the policies are in effect and enforcing the changes immediately. Simple concurrent control algorithms for realtime update of access control policy were given in the model. The model and algorithms are useful for concurrent environment in which multiple subjects access and modify data and access control policies, while the policies are in effect.

Key words: information security, access control, real-time update, concurrent control

摘要： 为了保证在动态环境下信息系统的安全性，需要一个良好的访问控制模型，对访问控制策略的实时变化立即作出反映，并采取必要的措施。描述了一种支持访问权限实时更新的访问控制模型和实现，并进行了并发性分析。在这种模型中，访问权限实时更新的并发控制算法简单且易于实现。在并发环境中，多个主体读写数据和修改访问控制策略并互相影响时，可直接应用该模型与算法。

关键词: 信息安全, 访问控制, 实时更新, 并发控制