| 摘要 |
<p>A secure computer system comprising at least one terminal incorporating a screen and a keyboard, and means to prevent, limit or suspend access to the system from the terminal until a user keys in a code via the keyboard. Information is displayed on the screen from which the code can be derived when it is required by the system for the code to be keyed in to initiate, extend or regain access to the system. A responder unit detects the displayed information, derives the code from the detected information, and displays the derived code to enable the user to key in the code. Interrogation routines are initiated to suspend access to the system during the course of a session of use of the system, each interrogation routine causing information to be displayed on the screen. The responder unit generates a code which when keyed in regains to the system.</p> |
