User-Directed Privacy Protection in the Ubiquitous Environment

In the ubiquitous environment, when a user obtains services from a domain and goes between domains, there is a need to move freely and have services provided continuously. Also, the service provider wants to authenticate a user easily. But a serious problem exists: How can a user's personal information be protected and how can a user control their information? In this paper, we propose a system to authenticate a user and protect personal privacy by securing personal data. This system can gather personal access records from the service provider and deliver them to the home domain server. In addition, the service provider can obtain user information by a legal process when necessary.