Patent ID: 8494166

Claim:
A method for enabling a plurality of users to perform respective write operations to respective user data portions of a storage medium comprising: generating a first data key; generating a derived data key from the first data key, the derived data key being calculated using the first data key and a unique value; using the derived data key as an encryption key for encrypting user data to provide encrypted user data; selectively writing the encrypted user data to a respective user data portion of the storage medium; and, writing the unique value to a KeyID field of an encrypted record header of the storage medium; and wherein the storage medium comprises a storage cartridge and at least one copy of the encryption key is stored in wrapped form on the storage cartridge; the storage cartridge comprises a magnetic tape and at least one copy of the derived data key is stored in wrapped form in at least one location on the magnetic tape; the at least one location on the magnetic tape comprises a non-user data area.