Simply wire some wire behind the keys and heat them in irregular patterns, also make them run quite hot. Don't make the wires to small to produce an IDable pattern upon the keys. Never let them cool to close to room temperature. That way whatever pattern there is in the heating (now cooling) of the buttons cannot be the buttons pressed. Also it keeps the snow of the board. Lewis 2011/8/23 Michael Nelson <nelson_mikel@yahoo.com>
J.A. Terranson wrote:
Old news. We were doing that in the early "aughts". Yes, it had a familiar ring to it... I was wondering what the UCSD people meant as their contribution. Presumably getting it to work in the ATM setting.
Same family of attacks as the thin powder or other film over the keypad. A friend of mine who worked for the govt, had an rsa "Pwnie-Token", and he said that after a several years the buttons that he used for the PIN developed indentations...
I'm waiting for a pinpad that maintains a
uniform temperature to get around this.
Hard to achieve sufficiently quick response. How about the keys have independent heating elements so that they can be randomized. And of course there is the distribution of heat across each key surface...
Mike