Authentication apparatus and image-forming apparatus

An image-forming apparatus comprising:

• an authentication unit configured to perform authentication on an authentication target apparatus that includes pre-stored first allowance data used to determine whether a response to an authentication request received from the authentication unit is allowed;
• and
• an image-forming unit configured to form an image on a sheet,
• wherein the authentication unit includes:
• timer circuitry configured to measure a time for which the authentication apparatus is energized;
• a memory storing restriction data that becomes readable after the time measured by the timer circuitry reaches a pre-set reference time;
• communication circuitry configured to transmit, to the authentication target apparatus, second allowance data based on the restriction data read from the memory, the second allowance data being subjected to verification by the authentication target apparatus using the first allowance data;
• and
• processing circuitry configured to perform authentication on the authentication target apparatus based on an authentication response received from the authentication target apparatus when the verification performed on the second allowance data by the authentication target apparatus with use of the first allowance data is successful.