Abstract: The Spatio-Temporal Access Control Model（STAC） in pervasive computing is proposed in this paper.Based on the Spatio-Temporal attributes of subjects and objects，the model authorizes the subjects dynamically.The problem of an access request for an object in some region which is issued from a subject who is in some other region at some period of time is also discussed.The main elements，the architecture and access control algorithm of the model are described.The STAC model provides the technology for dynamic spatio-temporal attributes based authorization in pervasive computing.

摘要： 提出了一种普适计算环境下的时空访问控制模型STAC（Spatio-Temporal Access Control Model）。该模型基于主体、客体的时空属性进行动态授权，研究了主体在一定时间范围、一定空间区域内访问另一空间区域内客体的授权问题，描述了STAC模型的构成要素、体系结构和访问控制算法。该模型为解决普适计算环境下动态时空访问控制授权问题提供了一定的技术手段。