| 摘要 |
PURPOSE:To automatically detect the illegal use even in the case an identification character- string leaks out by changing dynamically the qualification confirming procedure from a computer side, at the time of confirming whether an operator of a terminal is qualified to use a computer or not at the time of starting the communication. CONSTITUTION:A computer generates one piece of identification character-string dynamically every time by an identification character-string generating function 1, an identification character-string recording function 2 records in time series the maximum N pieces of identification character-strings at each separate discrimination code, and an identification character- string transmitting function 3 transmits the latest identification character-string to a terminal. An identification characterstring recording function 5 of the terminal records in time series the maximum N pieces of received identification character-strings, and an identification character-string transmitting function 6 transmits the maximum N pieces of recorded identification character-strings in order to time series. With regard to the maximum N pieces of character-strings received from the terminal, an identification character-string comparing function 4 of the computer inspects whether the identification character-strings coincide separately or not, and whether the identification character-string is omitted in time series or not, and decides that the operator is qualified to use the computer only in the case both of them coincide with each other. In such a way, leaking-out of the identification character- string can be detected by the computer side in an early state. |
