The evolution of mobile technologies will enable us to realize the ubiquitous computing environment. In such environment, a user's mobile terminal manages his sensitive information and assists in his activities. At the same time, information leakage will become more serious social problems. In this paper, we propose a framework which protects user's sensitive information according to a way the user supposes safe. In the framework, a user offers a program, which implements a way the user supposes safe, to an information recipient. And then, the information recipient makes use of the user's sensitive information through the program. In this manner, the user can protect his sensitive information. The framework, however, has a problem, by which the information recipient may analyze the program and obtain some sensitive information. In this paper, we introduce a tamper-proof device and trust relationship for a solution of this problem.