Abstract: In order to prevent leakage of an authentication symbol string such as a credit card number, and enable a user to be authenticated: an ID issuance server 20 receives the first eight digits of the credit card number from a portable telephone device 10 of the user and issues a one-time ID to the portable telephone device 10; and a service provision server 30 receives the last eight digits of the credit card number and the one-time ID from a PC 11, and transmits the one-time ID and those last eight digits to a number construction and authentication processing server 40 that receives the one-time ID and the last eight digits from the service provision server 30, communicates with the ID issuance server 20 and acquires the first eight digits which correspond to the one-time ID, reconstructs the credit card number, and performs authentication.

Abstract: An information processing device, which is used by a user and includes a storage device, encodes target information required for a device authentication by a server by using device-specific information or information based on the device-specific information as an encryption key, and stores the encoded target information. The information processing device uses a decryption key that corresponds to the encryption key used in the generation of the stored encoded target information to decode the encoded target information, and sends the decoded target information to the server. The server receives the target information from the information processing device, and determines whether or not the received target information is correct.

Abstract: An information processing device, which is used by a user and includes a storage device, encodes target information required for a device authentication by a server by using device-specific information or information based on the device-specific information as an encryption key, and stores the encoded target information. The information processing device uses a decryption key that corresponds to the encryption key used in the generation of the stored encoded target information to decode the encoded target information, and sends the decoded target information to the server. The server receives the target information from the information processing device, and determines whether or not the received target information is correct.

Abstract: In order to prevent leakage of an authentication symbol string such as a credit card number, and enable a user to be authenticated: an ID issuance server 20 receives the first eight digits of the credit card number from a portable telephone device 10 of the user and issues a one-time ID to the portable telephone device 10; and a service provision server 30 receives the last eight digits of the credit card number and the one-time ID from a PC 11, and transmits the one-time ID and those last eight digits to a number construction and authentication processing server 40 that receives the one-time ID and the last eight digits from the service provision server 30, communicates with the ID issuance server 20 and acquires the first eight digits which correspond to the one-time ID, reconstructs the credit card number, and performs authentication.

Abstract: In order appropriately to prevent leakage of an authentication symbol string such as a credit card number, and for it to be possible for a user to be authenticated as a legitimate user: an ID issuance server 20 receives the first eight digits of the credit card number from a portable telephone device 10 of the user and issues a one-time ID to the portable telephone device 10; a service provision server 30 receives the last eight digits of the credit card number and the one-time ID from a PC 11, and transmits the one-time ID and those last eight digits to a number construction and authentication processing server 40; and the number construction and authentication processing server 40 receives the one-time ID and the last eight digits from the service provision server 30, communicates with the ID issuance server 20 and acquires the first eight digits which correspond to the one-time ID, reconstructs the credit card number, and performs authentication with the credit card number.

Abstract: Verification facilitating company or companies X and verifying company or companies (e.g., credit service company or companies) Y may respectively manage member ID(s) and password(s) of user(s) 1 in mutually separate and mutually secret fashion. User(s) 1 may send member ID(s) to verification facilitating company or companies X from mobile telephone(s) 2, and verification facilitating company or companies X may use originating telephone number(s) and/or member ID(s) to carry out first-stage identity check(s). In the event of positive verification of identity as a result of such identity check(s), verification facilitating company or companies X may issue one-time ID(s) to user(s) 1 and may communicate such one-time ID(s) to verifying company or companies (e.g., credit service company or companies) Y. User(s) 1 may send one-time ID(s) and password(s) to verifying company or companies (e.g., credit service company or companies) Y from company or companies (e.g., store or stores) Z.