- Thanks to the spread of mobile technologies, we can access to the network anytime and from anywhere. In the near future, we will enable to realize the ubiquitous computing environment, in which user's mobile terminal assists in their activity. In the ubiquitous computing environment, user's mobile terminal manages personal information, which is used for negotiations with a service provider. However, various privacy problems, such as information leakage cases, have happened, so that we desire to protect our personal information. We propose a framework for protecting personal information. A basic idea of the framework is to make use of personal information through a program which the owner of personal information knows the behaviour of. We call this program trusted program, because the owner of personal information can trust a way of personal information use. Then, a user offers his/her trusted program to a service provider and compels the service provider to make use of his/...