Abstract: Context information is one of the key factors in pervasive access control systems, and produces the decisive influence on authorization and permission control on the subjects in pervasive computing environments. The security threshold intensity and the security policies should rectify according to the changes of context information, which has not been taken into consideration by traditional access control models, not fitting for the pervasive computing environment. In order to deeply adapt to the pervasive computing environment, the idea of security threshold intensity and security policies adjusted according to the changes of context information is proposed. A context related production rules based on the interval-valued fuzzy theory are produced, and a simple efficient interval value fuzzy access control method is designed to improve the adaptivity of the security threshold intensity and security policies in pervasive computing systems.

Key words: access control, interval-valued fuzzy reasoning, adaptivity, security policy, pervasive computing

摘要： 普适环境中的上下文信息是普适访问控制的关键因素，对主体的授权和对主体使用权限过程的控制具有决定性影响。系统安全强度和安全策略应随上下文的变化而动态改变。传统访问控制模型均未考虑上下文对安全强度和安全策略的动态影响，不适合普适计算环境。提出了普适环境下安全强度和安全策略随上下文动态变化的思想，基于区间值模糊集合理论建立了上下文信息相关的产生式规则，设计了一种简单高效的区间值模糊访问控制方法，以提高普适计算系统中安全强度和安全策略的自适应性，更符合普适环境。

关键词: 访问控制, 区间值模糊推理, 自适应, 安全策略, 普适计算