I find a hateful peculiarity of Android its nagging usual changes between versions in the paths for some system files and configuration variables. Even when I assume it is expectable on newborn operating systems.
I have read that the PIN number for unlocking the screen is stored (cyphered, I pressume) at
/data/system/password.key . So, for example, if I do:
# rm /data/system/password.key
... I will be able to delete it (of course priorly mounting the partition system as read/write, booting via Recovery, connecting via ADB shell, on a rooted device... blah blah blah).
Could this change work on every version of Android? Or this storage file is version-dependent?