... or, some numbers in the PIN require being pressed some random number of times until the key graphically indicates it is accepted. 1-8-1-4-5 might need to be

... or, some numbers in the PIN require being pressed some random number of times until the key graphically indicates it is accepted. 1-8-1-4-5 might need to be entered as 1-1-8-1-4-4-4-5-5 with the repeat number differing each time. Or the PIN pad can be presented with a random requirement to slide between 2 or 3 sequential digits rather than lift and tap. Tap-1-Slide-8-1-4-Tap-5.