Use two fingers to put in your PIN
One actually presses, the other one doesn’t
You could generate an absurd amount of possible PINs that could work on your card, giving any PIN peepers a seriously hard time, should they somehow have the intent to get ahold of your card and PIN through spying and pickpocketing
Safes, doors, etc. same principle
Even better tip: commit your false finger movements to muscle memory so not even a recurring stalker can bypass it
This will be totally overboard, and totally unnecessary, most of the time. But like any kind of security, it’s good to have it even if you hopefully never need it
Thermal camera will reveal the buttons your fingers lingered on and in roughly what order as they cool.
That’s why I spend a few minutes afterward licking the keypad to lay false heat signatures and promote faster cooling due to saliva. Attackers/observers are temporarily stunned with confusion and disgust, giving me a brief window to escape unnoticed.
Making sure that machine is warmed up for whatever deposit or withdrawal you had in mind?
Also dissolves some of the oils your hand left behind, which any 2 bit criminal with a forensics lab would pick up on in a second
Easily defended against: Upon finishing your transaction, simply press every single button on the machine in quick succession, with roughly equal firmness.
One of the keypad locks I have on my door requires you press two random numbers after your pin, which I always thought was pretty clever. The one my parents have rotates the numbers, which also works but is reallllly not compatible with being drunk.
What if I use something else to press the buttons with one hand and covering with the other hand?
Did you learn that from the game Splinter Cell? I remember using that trick, I feel like the odds of it working reliably IRL are extremely low though and also requires a thermal camera.
Somebody, maybe a youtuber, demo’d it on a checkout, maybe at a Target. I can definitely see fingerprints with my thermal camera, even after brief touches, and there’s phones now with built-in thermal cams. You do need a pretty cool and uniform temperature keypad, so not one with electronics close behind it, and you have to image the keypad pretty close due to low resolution and pretty soon after the victim leaves - waiting for a receipt would normalize the temps. So, yeah, not a very practical attack.
But I feel like this whole thread is topic is pretty high on the improbable and unrealistic scale.