Pervasive Computing

Aim is to create a pervasive computing environment. that means.... there is one central server that stores all the usernames and passwords ie. the authentication stuff. the data of the users are stored in all the systems in a distributed manner. the user can login at any system and has access control over his data alone. ie. his data may or may not be present in the system where he has logged in. or not in any one particular system. it is distributed everywhere. anybory intrested plz reply...