Abstract: A server issues challenge data and transmits the challenge data to a client. The client stores encrypted group data including a plurality of encrypted data encrypted with a server key, and parameter data A, in a memory, receives the challenge data, generates response data using a response key on the client side, and transmits the response data, the encrypted group data, and the parameter data A to the server. The server selects encrypted data to be used from the received encrypted group data, based on the received parameter data A, sets a response key on the server side, based on the selected encrypted data and data decrypted with the server key, verifies the received response data, based on the challenge data and the response key on the server side, and notifies a result of the verification to the client. The client receives the notification.

Abstract: A server issues challenge data and transmits the challenge data to a client. The client stores pre-calculated data obtained by executing at least a part of calculation for setting a server response key, sets a client response key without using the pre-calculated data, generates response data from the challenge data received from the server, based on the client response key, and transmits the response data and the pre-calculated data to the server. The server receives the response data and the pre-calculated data, sets the server response key, based on the pre-calculated data, verifies the response received from the client, based on the issued challenge data and the server response key, and notifies the client of a result based on the verification.

Abstract: A server issues challenge data and transmits the challenge data to a client. The client stores a first parameter, receives the challenge data, generates response data from the challenge data using a response key on the client side, and transmits the response data and the first parameter to the server. The server further receives the response data and the first parameter, specifies seed data for calculation for setting a response key on the server side, using the first parameter, sets the response key on the server side by executing the calculation using the seed data, verifies the response data using the challenge data and the response key on the server side, and notifies a result thereof. The client receives the result.

Abstract: A server generates challenge data by generating falsification verification data of first data, using a server key, based on a predetermined algorithm, and transmits the first data and the challenge data to a client. The client receives the first data and the challenge data, generates response data from the received challenge data using a response key in the client, and transmits the received first data and the response data to the server. The server receives the transmitted first data and response data and reproduces challenge data by generating the falsification verification data using the server key, based on the predetermined algorithm. Then, the server verifies the received response data using the reproduced challenge data and a response key in the server, and if a verification result is positive, the server notifies a positive authentication result.

Abstract: A server issues challenge data and transmits the challenge data to a client. The client stores encrypted group data including a plurality of encrypted data encrypted with a server key, and parameter data A, in a memory, receives the challenge data, generates response data using a response key on the client side, and transmits the response data, the encrypted group data, and the parameter data A to the server. The server selects encrypted data to be used from the received encrypted group data, based on the received parameter data A, sets a response key on the server side, based on the selected encrypted data and data decrypted with the server key, verifies the received response data, based on the challenge data and the response key on the server side, and notifies a result of the verification to the client. The client receives the notification.