1. A method for restricting access to data stored in a storage subsystem, the method comprising: storing at least one data string including a unique identifier of the storage subsystem in an address location in a restricted area of the storage subsystem, said restricted area accessible to a host system via an ATA vendor-specific memory access command to the storage subsystem and not accessible via a standard ATA memory access command, wherein the address location is selected according to a selection method that varies data string storage location in the restricted area across a plurality of storage subsystems; encrypting a data file to create a device-specific file, the encrypting being based at least in part on the at least one data string including the unique identifier of the storage subsystem to inhibit decryption of the device-specific file when it is copied to another storage subsystem; and storing the device-specific file on the storage subsystem, the device-specific file being accessible by the host system through a standard ATA memory access command and capable of being decrypted by using the at least one data string.