摘要 |
This invention aims at effectively preventing reception of illicit authentic code information from a user terminal without requesting any heavy load on the administrator. To accomplish this, an authentication system creates first display data on the basis of second display data required to display a form without any authentication code input field, and script information required to additionally display the authentication code input field on the form, and provides it to the user terminal. Information input to the authentication code input field is received from the user terminal, and it is authenticated if the information is authentic. For example, when a predetermined condition is met (e.g., the number of times of reception of unauthentic information is equal to or smaller than a predetermined value), the first display data is transmitted to the user terminal. On the other hand, when the predetermined condition is not met, the second display data is transmitted to the user terminal. |