In ubiquitous computing environment, people carrying their mobile devices (eg., mobile phone, PDA, embedded devices) expect to access locally hosted services or resources anytime, anywhere. These mobile devices have restricted capabilities and security supports. Traditional security management systems used definite access control policies for each role or user in each domain server or agent. But in ubiquitous environment, it is hard to specify authorization policies for mobile users and it is inflexible and unavailable for security management of users or mobile devices. To solve these problems, we need trust-based management mechanism as a reference to security management systems. Trust model contains trust relationship and calculation of trust value. Experiences and recommendations are the factors to calculate trust value. In this paper, we design a trust model to calculate trust value and a trust management architecture which can be running in various domain servers and mobile devices.
