www.securitymagazine.com/articles/76751-scramblepad-keypad-reader-1
ScramblePad Keypad/Reader
August 14, 2003

Hirsch Electronics’ ScramblePad keypad/reader provides a high-security approach to access, because the credential (ID code or PIN number) cannot be accidentally shared with, or stolen by, onlookers. Each numeral is randomly scrambled to a new position each time the START button is pressed, so a bystander cannot ascertain the pattern.