A U-STOR-IT user connects to the service using a browser, with user authentication done using client-side certificates generated by the U-STOR-IT certificate authority. Access is controlled by policy; access to an individual locker or file within a locker is determined by policy statements that may reside in several users' policy files. Each user has a policy file, but the policy language allows one user to refer to the policy of another user.
In addition to storing files, U-STOR-IT has message processing and version control facilities, providing a secure collaboration tool centered around policy concepts expressed in RT.
A version of U-STOR-IT is (or was) running. Here is a user guide.