Abstract: The state of subjects/objects and the current context have the decisive effect on the authorization result in pervasive computing environment. Focusing on the problem that current authorization models use simple states of subjects/objects and the context information leads to failure in pervasive computing environment, a novel dynamic access control model based on the state of subjects/objects and the current context was proposed. The main elements, the architecture and the authorization algorithm of the model were described. Compared to the existing authorization models, the unified scheme of the context information proposed to affect the authorization result enhances the expression ability of the model, and makes the model simple as well. The model is more suitable for pervasive computing environment.

Key words: access control, authorization model, pervasive computing, context awareness

摘要： 普适计算环境下，主体、客体的状态和上下文信息对授权结果具有决定性影响。针对已有授权模型由于主体、客体状态和上下文信息的缺失而导致模型不适合普适计算环境的问题，提出了一种基于主体、客体的状态和环境上下文信息对主体进行动态授权的访问控制模型，论述了模型的构成元素、体系结构和授权算法。与已有模型相比新模型采用统一的模式描述上下文信息对授权的影响，既保证了模型的简单性，又增强了模型的表达能力，更适合于普适计算环境。

关键词: 访问控制, 授权模型, 普适计算, 上下文感知