| CPC H04L 9/3271 (2013.01) [H04L 9/0838 (2013.01); H04L 9/0869 (2013.01); H04L 9/0891 (2013.01)] | 21 Claims |
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1. An authentication system for authenticating an authentication-target apparatus by transmitting challenge data from an authenticating apparatus to the authentication-target apparatus and transmitting response data from the authentication-target apparatus to the authenticating apparatus,
wherein the authentication-target apparatus comprises:
a first non-volatile memory that stores a secret key of the authentication-target apparatus and an encrypted original key generated by encrypting an original key using the secret key;
a first decryptor that reproduces the original key, which was used to generate the encrypted original key, by decrypting the encrypted original key using the secret key stored in the first non-volatile memory;
a first volatile memory that temporarily holds the reproduced original key obtained by the first decryptor;
a first random number generator that generates a random number;
a first encryptor that generates a new encrypted original key by obtaining a copy of the reproduced original key held by the first volatile memory and encrypting the copy of the reproduced original key obtained from the first volatile memory using the random number as a new secret key; and
a first processor configured to update the secret key and the encrypted original key stored in the first non-volatile memory using the new secret key and the new encrypted original key, derive an authentication key based on the reproduced original key held in the first volatile memory, identification information of the authenticating apparatus, and identification information of the authentication-target apparatus, and generate the response data based on the challenge data received from the authenticating apparatus and the authentication key derived by the first processor, and
the authenticating apparatus comprises:
a second non-volatile memory that stores a secret key of the authenticating apparatus and an encrypted original key generated by encrypting an original key using the secret key;
a second decryptor that reproduces the original key, which was used to generate the encrypted original key stored in the second non-volatile memory, by decrypting the encrypted original key using the secret key stored in the second non-volatile memory;
a second volatile memory that temporarily holds the reproduced original key obtained by the second decryptor;
a second random number generator that generates a random number;
a second encryptor that generates a new encrypted original key by obtaining a copy of the reproduced original key held by the second volatile memory and encrypting the copy of the reproduced original key obtained from the second volatile memory using the random number generated by the second random number generator as a new secret key; and
a second processor that updates the secret key and the encrypted original key stored in the second non-volatile memory using the new secret key and the new encrypted original key, derives an authentication key based on the reproduced original key held in the second volatile memory, identification information of the authenticating apparatus, and identification information of the authentication-target apparatus, generates response data for verification based on the challenge data and the authentication key derived by the second processor, and obtains an authentication result based on the response data transmitted from the authentication-target apparatus and the response data for verification,
wherein the authentication-target apparatus deletes the reproduced original key held in the first volatile memory when the authentication key is derived by the first processor,
wherein the authenticating apparatus is an image forming device, and the authentication-target apparatus is a replaceable component or a consumable that can be attached to and removed from the image forming device, and
wherein the replaceable component or the consumable is allowed to operate in response to the obtained authentication result being successful.
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