To provide a system for performing settlement even in a state that the substance of a credit card is lost.
A user inputs user ID and sum information about a payment sum to a user device, and a user device generates a one-time password, and sends user ID, sum information and one-time password to an authentication device. The authentication device authenticates the validity of a user by the user ID and the one-time password, and when the user is valid, records the user ID, sum information and one-time password sent from the user device, and sends the notification of authentication success to the user device. The user device generates set data by integrating the user ID, the sum information and the one-time password, and transfers the set data to the other party of payment.
Yoshito Muramatsu
Ryota Sano