A disk array device comprises a first storage unit that stores encrypted user data, a second storage unit that is different from the first storage unit and locks and stores configuration information including a first encrypted authentication key that unlocks the encrypted user data, a management unit that includes a decoder that decodes the first encrypted authentication key and a control unit that unlocks the locked configuration information using a second authentication key, the management unit managing data using the first and second authentication keys. the management unit includes a configuration information recovery portion that unlocks the locked configuration information by using the second authentication key and recovers the configuration information during booting and a user data unlocking portion that decodes the first encrypted authentication key included in the configuration information and unlocks the encrypted user data stored in the first storage unit by using the first decoded authentication key.