Abstract: A personal data device, system and method for storing personal data including authentication means for restricting access to the stored personal data to an authorized user and communication means for transferring at least some of the personal data between the personal device and a server. A copy of the personal data is stored on a database server and the data on the personal data device and the data on the database server is mutually updated and synchronized by communications over a communications network. A facility is supplied to delete the personal data stored on the personal data device when attempts are made by an unauthorized user to use the personal data device. The personal data may subsequently be reloaded into the personal data device, or into a replacement personal data device, from the database server.