| 摘要 |
PURPOSE:To prevent the foul use of a system even in case the confirmed information is wiretapped by providing the confirmed information groups to a host computer as well as terminals and converting and exchanging periodically those information groups to check the protection of secrecy. CONSTITUTION:When a terminal operator feeds an exchange key when the processing is over with an LOGON command, etc., a terminal system 3 converts a confirmed information group table 4 and then produces a confirmed information group table 6. At the same time, the system 3 sends the exchange key to a host computer system 1. Thus the system 1 converts the table 4 in the same way and produces the table 6. Then the pairs of the retrieving numbers of the confirmed information read out periodically and at random from the table 6 and the corresponding confirmed information are sent to one side from the other side. The receiver side compares those pairs with the contents of its own table 6 and permits the subsequent uses if the coincidence is obtained from the comparison. In case no coincidence is obtained or the pairs of confirmed information are not delivered for a fixed period or longer, a link is cut to a terminal to inhibit the subsequent system uses. |
