Composite sensor model and security agent to improve privacy of ubiquitous computing

With the development of electronic and networking technologies, ubiquitous computing is now an exploring focused area. Due to characteristics of ubiquitous computing, privacy and security issues are always quite challenging for application development. This paper presents a novel paradigm to enhance the privacy and security in ubiquitous environments. Unlike previous context model, the proposed composite sensor-based context model (ComSensor) captures both complicated context entities and security requirements. Security agent governs security and privacy by privacy rules defined in ComSensor. One security agent is responsible for privacy management for one context objects. Sensitive context raw data and information are kept only in distributed security agents, from which context queries are processed and context information is disclosed in different accurate levels according to privacy rules. Based on ComSensor and security agent, decentralized trust management architecture is proposed, which is appropriate for different kinds of ubiquitous applications. Examining results on a prototype show that this paradigm is scalable and runs in real-time mode.