Where to find a PIN lock screen that scrambles the keypad on every use? Is there some way to get a lock screen whose PIN pad changes number layouts every time it's used? It seems like a very basic way to thwart smudge attacks and yet my (broken?) google-fu can't find any implementations.

I'm using 2.3 Gingerbread, would prefer solutions not involving rooting/flashing new ROMs if possible.
You have a great point, and a valid question. Looks like this was raised as an enhancement request two years ago, if that means anything. I found two apps that seek to address your concern:


Whisper Systems has a different method of working around smudge issues by asking users to wipe over the smudges they just created.
Number Track Lock advertises the exact functionality you're looking for. This is a paid app that has mediocre reviews, so proceed at your own risk.


Neither of these to me are a perfect solution. I'd love to see this built into Android - perhaps you can find a ROM with something like this baked in?