Randomised coded electronic security access method - using pushbuttons associated with characters in random sequence controlled by microprocessor

摘要

The appts. comprises a key-pad (11) in which each key or button is associated with a display device (10). A microprocessor (1) allocates characters at random to each key. Entry of the correct code by pressing appropriate keys in sequence allows access. The allocation of characters to keys is re-organised after each use, or when the user determines. Alternatively, a video touch screen may be used. ADVANTAGE - Randomised electronic security system prevents acquisition of codes by unauthorised observation.