Authentication apparatus, authentication target apparatus, image forming apparatus, replacement unit, and authentication method

An authentication target apparatus to be authenticated by an authentication apparatus, the authentication target apparatus comprising:

• a storage unit configured to store one or more pieces of authentication information;
• a first generation unit configured to generate encryption processing information;
• a decryption unit configured to receive encrypted first data from the authentication apparatus, perform decryption processing on the first data in accordance with the encryption processing information generated by the first generation unit, and output second data;
• a second generation unit configured to generate authentication data based on selected authentication information from among the one or more pieces of authentication information stored in the storage unit and challenge data included in the second data;
• and
• an encryption unit configured to perform encryption processing on third data including the authentication data in accordance with the encryption processing information generated by the first generation unit and thereby generate fourth data, and to transmit the fourth data to the authentication apparatus,
• wherein the first generation unit is configured to change the encryption processing information in accordance with a predetermined rule when either of the decryption processing and the encryption processing is performed.

A replacement unit of a predetermined apparatus including an authentication apparatus, wherein

• the replacement unit comprises an authentication target apparatus, and
• the authentication target apparatus comprises:
• a storage unit configured to store one or more pieces of authentication information;
• a first generation unit configured to generate encryption processing information;
• a decryption unit configured to receive encrypted first data from the authentication apparatus, perform decryption processing on the first data in accordance with the encryption processing information generated by the first generation unit, and output second data;
• a second generation unit configured to generate authentication data based on selected authentication information from among the one or more pieces of authentication information stored in the storage unit and challenge data included in the second data;
• and
• an encryption unit configured to perform encryption processing on third data including the authentication data in accordance with the encryption processing information generated by the first generation unit and thereby generate fourth data, and to transmit the fourth data to the authentication apparatus, and
• wherein the first generation unit is configured to change the encryption processing information in accordance with a predetermined rule when either of the decryption processing and the encryption processing is performed.

An authentication apparatus for authenticating an authentication target apparatus, the authentication apparatus comprising:

• a storage unit configured to store one or more pieces of verification information;
• a first generation unit configured to generate encryption processing information;
• a second generation unit configured to generate challenge data;
• an encryption unit configured to perform encryption processing on first data including the challenge data in accordance with the encryption processing information generated by the first generation unit and thereby generate second data, and to transmit the second data to the authentication target apparatus;
• a decryption unit configured to receive encrypted third data from the authentication target apparatus as a response to having transmitted the second data to the authentication target apparatus, and generate fourth data by performing decryption processing on the third data in accordance with the encryption processing information generated by the first generation unit;
• a third generation unit configured to generate verification data based on selected verification information from among the one or more pieces of verification information stored in the storage unit and the challenge data;
• and
• an authentication unit configured to authenticate the authentication target apparatus by comparing authentication data based on the challenge data included in the fourth data and the verification data,
• wherein the first generation unit is configured to change the encryption processing information in accordance with a predetermined rule when either of the decryption processing and the encryption processing is performed.

An image forming apparatus in which a replacement unit comprising an authentication target apparatus is mounted and for performing image formation, the image forming apparatus comprising an authentication apparatus,

• wherein the authentication apparatus comprises:
• a storage unit configured to store one or more pieces of verification information;
• a first generation unit configured to generate encryption processing information;
• a second generation unit configured to generate challenge data;
• an encryption unit configured to perform encryption processing on first data including the challenge data in accordance with the encryption processing information generated by the first generation unit and thereby generate second data, and to transmit the second data to the authentication target apparatus;
• a decryption unit configured to receive encrypted third data from the authentication target apparatus as a response to having transmitted the second data to the authentication target apparatus, and generate fourth data by performing decryption processing on the third data in accordance with the encryption processing information generated by the first generation unit;
• a third generation unit configured to generate verification data based on selected verification information from among the one or more pieces of verification information stored in the storage unit and the challenge data;
• and
• an authentication unit configured to authenticate the authentication target apparatus by comparing authentication data based on the challenge data included in the fourth data and the verification data,
• wherein the first generation unit is configured to change the encryption processing information in accordance with a predetermined rule when either of the decryption processing and the encryption processing is performed.