UNAUTHORIZED USE DETERMINATION SYSTEM, UNAUTHORIZED USE DETERMINATION METHOD, SERVICE PROVISION SERVER AND PROGRAM

PROBLEM TO BE SOLVED: To provide an unauthorized use determination system for determining unauthorized use even in the case of leakage of ID and a password, impersonation, or intentional leakage of the ID and the password for unauthorized sharing.SOLUTION: A terminal side position information acquisition unit 21 acquires a current position of a terminal. An information transmission and reception unit 22 transmits the acquired current position and user authentication information to a user authentication unit 12. The user authentication unit 12 receives the current position and the user authentication information, authenticates a user by using the user authentication information, and, when the authentication is successful, stores a current time and the current position. An unauthorized use determination unit 13 acquires the user identification information, the current time, and the current position from the user authentication unit 12; transmits the previous time and position when the user previously used the service, and the current position to a minimum movement time calculation unit 31; and, when the minimum movement time calculated by the minimum movement time calculation unit 31 is larger than a difference between the current time and the previous time, determines as unauthorized use.