A secure context distribution framework for peer-based pervasive systems

Pervasive computing envisions seamless and distraction-free application support for everyday user tasks. Achieving this requires a high degree of automation. In many scenarios, the basis for automation is context information that can be acquired unobtrusively by means of sensors. Consequently, it is vital to ensure the validity of the context information, especially, in cases where automatic decisions can have severe security implications. In smart environments, the validity of context information can be ensured simply using a centralized context storage that is securely connected to all trusted sensors. In peer-based systems such a centralized approach cannot be applied. Instead, it is necessary to use all devices to distribute context information which requires additional precautions to ensure its validity. In this paper, we derive the requirements on secure context distribution for peer-based systems. Furthermore, we describe a generic distribution framework to enable the usage of context information in security critical applications. On the basis of a prototypical implementation, we present an evaluation indicating that the proposed framework can achieve a high level of security while being applicable to many scenarios.