I've done this for year when entering my pin code for making payments or cash withdrawals. I position my hand so that it obscures all the keys, and then move on

I've done this for year when entering my pin code for making payments or cash withdrawals. I position my hand so that it obscures all the keys, and then move one finger a tiny bit that does the actual key press, and another finger in an obvious way to make it seem as if I'm pressing another key as the one I'm actually pressing.