A data storage system stores logical data object(s), each identified by a logical identifier. A control is configured to assign a unique WORM (Write Once Read Many) identifier to the logical data object, and stores the unique WORM identifier as associated with the logical identifier, in a database maintained by the control so as to be persistent. Data storage is configured to write the logical data object with a header with the unique WORM identifier. The control, in order to allow the logical data object to be accessed externally to the control, requires matching the unique WORM identifier in the header of a logical data object to the unique WORM identifier of the persistent database for the logical object. The unique WORM identifier is formed of a checksum hash value related to nonce fields comprising at least the logical identifier of the logical data object, an incrementing token, and a time stamp.