Patent ID: 8074075

Claim:
An authentication system including a transmitting terminal, a receiving terminal and an authentication device that are connected via a communication line, the transmitting terminal comprising: message transmitting unit to transmit and register a message to and in the authentication device; information storage unit to be stored with plural items of information related to the receiving terminal; selecting unit to select information to be adopted and information not to be adopted among information stored in the information storage unit according to the user operation as authentication information for accessing the message; and authentication information transmitting unit to transmit the authentication information including plural items of the adopted information related to the receiving terminal to the authentication device, the authentication device comprising; message receiving unit to receive the message from the transmitting terminal; authentication information receiving unit to receive the authentication information including the plural items of the adopted information related to the receiving terminal from the transmitting terminal; registering unit to register the message and the authentication information in a way that associates the message and the authentication information with each other; request receiving unit to receive a request showing a purport of acquiring the message and the authentication information for acquiring the message from the receiving terminal; authenticating unit to authenticate the receiving terminal, if both the authentication information including item of information received from the receiving terminal and the authentication information including the plural items of the adopted information related to the receiving terminal registered on the registering unit, which the authentication information receiving unit receives from the transmitting terminal, are coincident with each other; and message transmitting unit to transmit, if the authenticating unit authenticates the receiving terminal, the message corresponding to the authentication information to the receiving terminal, the receiving terminal comprising: message request unit to request acquisition of the message; authentication information transmitting unit to transmit the authentication information for acquiring the message to the authentication device; and message receiving unit to receive the message from the authentication device.