Authenticator, authenticatee and authentication method

An authenticatee device comprising:

• a memory configured to store key information having a data structure composed of encrypted slot key sequences which are created by encrypting sequences of a slot index and a slot key, secret information of a matrix form corresponding to the slot index, and encrypted secret information which is created by encrypting the secret information based on the slot key;
• circuitry configured to
• generate a random number A;
• and
• generate a random number D which is composed of at least a part of both of the generated random number A and a random number B which is received;
• a compression arithmetic circuit configured to generate data C by executing a compression operation with respect to the random number D and the secret information loaded from the memory;
• the circuitry being further configured to generate data ν;
• and
• an addition circuit configured to generate a value Z from the data ν and the data C.

An authenticator device which authenticates an authenticatee device and includes a memory which stores key information having a data structure composed of encrypted slot key sequences, secret information of a matrix form, and encrypted secret information which is created by encrypting the secret information, the authenticator device comprising:

• processing circuitry configured to:
• select an encrypted slot key sequence corresponding to a device index of the authenticator from the encrypted slot key sequences which is received from the authenticatee device;
• decrypt the encrypted slot key sequence by a device key, thereby producing a sequence of a slot index and a slot key;
• select an element of corresponding to the slot index from the encrypted secret information which is received from the authenticatee device;
• execute a decryption process on the element of the encrypted secret information, by using the slot key, to produce an element of the secret information;
• generate a random number B;
• generate a random number D which is composed of at least a part of both of the generated random number B and a random number A which is received from the authenticatee device;
• generate data C by executing a compression operation using the random number D and the secret information;
• select, from calculated results received from the authenticatee device, a calculated result Z corresponding to the slot index;
• and
• execute a determination process by using the generated data C and the selected calculated result Z.

An authentication method between an authenticatee device having a first memory which stores an authenticatee ID and secret information and an authenticator device having a second memory which stores an authenticator ID and unique secret information, comprising:

• transmitting, by the authenticatee device, the authenticatee ID, which is requested, to the authenticator device;
• executing, by the authenticator device, a non-linear process on the authenticatee ID, which has been acquired, and the unique secret information possessed by the authenticator device, thereby obtaining a unique value;
• and
• executing, by the authenticatee device, a one-way function process on the authenticator ID, which has been transmitted, and the secret information possessed by the authenticatee device, thereby sharing the unique secret information;
• receiving, by the authenticatee device, a random number B which is generated by the authenticator;
• generating, by the authenticatee device, a random number A and data ν;
• generating, by the authenticatee device, a random number D using the generated random number A and the received random number B;
• generating, by the authenticatee device, data C by executing a compression operation using the random number D and the unique value;
• transmitting a calculated result Z, which is obtained from the data C and the data ν, to the authenticator device;
• generating, by the authenticator device, a random number D using the generated random number A and the received random number B;
• generating, by the authenticator device, data C by executing a compression operation using the random number D and the unique value;
• and
• executing, by the authenticator device, a determination process by using the received calculated result Z and the generated data C.

An authentication method between an authenticatee device having a first memory which stores a plurality of encrypted slot keys, secret information composed of a plurality of elements, and encrypted secret information which is created by encrypting the elements, and an authenticator device having a second memory which authenticates the authenticatee device, comprising:

• selecting, by the authenticator device, an encrypted slot key corresponding to a device index of the authenticator from the plurality of the encrypted slot keys, and decrypting the encrypted slot key by a device key, to produce a slot key;
• executing, by the authenticator device, a decryption process on the encrypted secret information by using the slot key to produce an element of the secret information;
• using a compression arithmetic circuit to perform an arithmetic operation on the element and produce an authentication value;
• and
• authenticating, in the authenticator device, the authenticatee device using the authentication value.

An authenticator device which perforins an authentication process on an authenticatee device having a first memory which stores key information having a data structure composed of encrypted slot key sequences, secret information of a matrix form, and encrypted secret information which is created by encrypting the secret information, and an authenticator device having a second memory, comprising:

• processing circuitry configured to:
• receive the encrypted secret information and the key information from the authenticate device;
• select an encrypted slot key sequence corresponding to a device index stored in the second memory of the authenticator device from the encrypted slot key sequences in the key information received from the authenticatee device, the device index corresponding to the authenticator device;
• decrypt the encrypted slot key sequence by a device key stored in the second memory, to produce a sequence of a slot index and a slot key;
• select an element corresponding to the slot index from the encrypted secret information;
• and
• execute a decryption process on the element of the encrypted secret information by using the slot key to produce an element of the secret information;
• and
• a compression arithmetic circuit configured to perform an arithmetic operation on the element and produce an authentication value, wherein the processing circuitry is further configured to authenticate the authenticatee device using the authentication value.