An information processing apparatus comprising: a plurality of encryption algorithm units which are respectively capable of performing mutual authentication by respectively using an encryption method having a cipher key, each encryption method and cipher key being different from one another, the mutual authentication being with an external device; and a data memory unit which stores a plurality of cipher-specific information being provided to each of the encryption algorithm units and including an encryption method used by each of the encryption algorithm units and disabling control information for disabling at least one encryption algorithm unit among the plurality of encryption algorithm units; wherein the disabling control information includes a valid encryption method list for distinguishing a valid encryption method among encryption methods used by the plurality of encryption algorithm units, and further includes a disabling encryption method list for distinguishing an encryption method to be disabled by a first encryption algorithm unit, a disabling encryption method also being listed as a valid encryption method; and wherein each of the encryption algorithm units is permitted by the information processing apparatus to attempt mutual authentication with an external device only in a case that an encryption method which is specified by an authentication request received from the external device is included in the valid encryption method list which is stored in the data memory unit, and wherein a first encryption algorithm unit is adapted to disable another encryption algorithm unit when the mutual authentication by the first encryption algorithm unit with the external device succeeds, by deleting an encryption method from the valid encryption method list stored at the data memory unit which matches with an encryption method from the disabling encryption method list, but only if the mutual authentication with an external device is performed specifying an encryption method that does not match with an encryption method from the disabling encryption method list, so that the disabled encryption algorithm unit becomes incapable of performing mutual authentication with an external device thereafter. a plurality of encryption algorithm units which are respectively capable of performing mutual authentication by respectively using an encryption method having a cipher key, each encryption method and cipher key being different from one another, the mutual authentication being with an external device; and a data memory unit which stores a plurality of cipher-specific information being provided to each of the encryption algorithm units and including an encryption method used by each of the encryption algorithm units and disabling control information for disabling at least one encryption algorithm unit among the plurality of encryption algorithm units; wherein the disabling control information includes a valid encryption method list for distinguishing a valid encryption method among encryption methods used by the plurality of encryption algorithm units, and further includes a disabling encryption method list for distinguishing an encryption method to be disabled by a first encryption algorithm unit, a disabling encryption method also being listed as a valid encryption method; and wherein each of the encryption algorithm units is permitted by the information processing apparatus to attempt mutual authentication with an external device only in a case that an encryption method which is specified by an authentication request received from the external device is included in the valid encryption method list which is stored in the data memory unit, and wherein a first encryption algorithm unit is adapted to disable another encryption algorithm unit when the mutual authentication by the first encryption algorithm unit with the external device succeeds, by deleting an encryption method from the valid encryption method list stored at the data memory unit which matches with an encryption method from the disabling encryption method list, but only if the mutual authentication with an external device is performed specifying an encryption method that does not match with an encryption method from the disabling encryption method list, so that the disabled encryption algorithm unit becomes incapable of performing mutual authentication with an external device thereafter.