It is an object to identify, for example, a subject who generates a certain event in addition to certifying a time and/or a location of the event. A terminal device 200 sends positioning information and a time from a GPS satellite 103 and biometric information of a user to an authentication server device 300 to request for issuance of a certification code 104. The authentication server device 300 carries out biometric authentication of the user by comparing the biometric information received from the terminal device 200 with reference data of the user which is maintained beforehand. When the biometric authentication succeeds, the authentication server device 300 generates the certification code 104 by combining the reference data, the time, a hashed value of a weather satellite image, and the positioning information used for the biometric authentication. The terminal device 200 receives the certification code 104 from the authentication server device 300 and uses the certification code 104 received by outputting to a label, a photo, an IC (integrated circuit) tag, etc.