| 摘要 |
<p>Changes to a record in a file stored on an electronic token (10) is effected by storing a change detection code (SCDC)(206) so that a change detection applet can calculate a current CDC for corresponding record(s), and compare the current CDC with the stored CDC to determine if data has changed. Any changes to records are registered by a registering element that provides a service feature, back-up of the file and/or synchronizes the file with other files stored remotely. One use of the method is to back-up phonebook records on subscriber identity module (SIM) cards.</p> |
