Patent ID: 6049790
Filing Date: 2000-04-11
Classification: G06F,G06Q,H03K

Abstract:
Protected keypad apparatus for entering data into a machine, said keypad including n sensitive zones, a detection sensor associated with each sensitive zone for detecting actuation of the associated sensitive zone, and a keypad driver unit for driving said keypad, said protected keypad apparatus being characterized in that it further includes:n individual processing circuits (14i), and n sensors (24), each circuit being associated with a sensor, each unit comprised by an individual processing circuit and its associated sensor having a physically monolithic structure forming a protected key, each circuit being associated with a respective sensitive zone and including encryption means (22, 26, 28, 30) for encrypting detection or non-detection of activation of the associated sensitive zone; andelectrical link means (16) for conveying data between said keypad driver unit (18) and each of said individual processing circuits;said driver unit and said individual circuits including means for periodically causing encrypted data indicating activation or non-activation of each of said sensitive zones to be conveyed to the driver unit.