| 摘要 |
PURPOSE:To prevent an illicit access by making it possible to judge that an object to be accessed is a permitted opposite party and further changing information specifying the permitted opposite party every time an access is performed. CONSTITUTION:When a host computer 10 responds when an access is performed from a terminal 30 to the host computer 10, the user name and the password for an illicit access prevention which are preliminarily assigned to a terminal are transmitted to the host side. The host 10 investigates whether these match with the matters registered in a storage device 11. When they match, a connection program is started, and the terminal identifier and the access sequence check data(ASC) from the terminal are received. These and the matters registered in the device 11 are compared. If they match, it is judged that the access is not illicit access, new ASC data is generated in the host 10 and the data is transmitted to the terminal 30. A ciphering processing is performed for the data, it is transmitted to the host 10, it is restored, and it is compared with the new generated ASC data. When they match, a desired program is started and a desired processing is performed. |
