上下文感知的动态访问控制模型

现有的访问控制技术主要依靠主体的标识来实现对系统资源的保护，在权限的控制时没有考虑执行的上下文环境。随着网络和分布式计算的发展，应用环境具有分布、异构、 动态的特点，需要考虑主体所处上下文进行动态的权限控制。本文提出了一个上下文感知的访问控制模型（DCAAC），DCAAC扩展了RBAC模型，增加了上下文约束。DCAAC从应 用环境中获取与安全相关的上下文信息来动态地改变用户的权限，同时保留了传统RBAC模型的优点。这一访问控制模型已在网格计算实验平台中实施。

A Dynamic Context-Aware Access Control Model

Despite the recent development in access control approaches,amongst them are the lack of context-aware models for access control,and the reliance on identity or capability-based access control schemes.With the development of networking and distributed computing,dynamic authorization through the security context must be enforced to cope with the distributed,heterogeneous and dynamic nature of these environments.In this paper,we present an access control scheme that can resolve these issues,and propose a dynamic context-aware access control model(DCAAC)which extends RBAC with context constraints.The DCAAC dynamically grants and adapts permissions to users based on a set of contextual information collected from the system and users' environments,while retaining the advantages of the RBAC model.A DCAAC model is implemented in our grid computing experiment.