SYSTEM, TERMINAL DEVICE, CONTROL METHOD, AND PROGRAM

摘要

PROBLEM TO BE SOLVED: To provide a system and the like suitable to prevent a fraudulent act, such as alteration of data.SOLUTION: A terminal unit 100 includes: a parameter storage part 101 storing parameters; a reception part 102 receiving instruction input; an update part 103 updating parameters based on instruction input; a request transmission part 104 transmitting a request to which parameters are designated to a server device at appropriate timing; and a response reception part 105 receiving a response from the server device. The server device includes: a request reception part receiving a request; a request storage part accumulating and storing the parameter and the request reception time; and an accumulation part for accumulating a parameter and time when the parameter and a recently stored parameter are within a predetermined range and a response transmission part transmitting a response. When the response reception part 105 does not receive a response within predetermined time, the update part 103 performs update by a parameter on which a penalty has been imposed.