But in the phone’s lockscreen, you are usually not bound by the 4-digit requirement of SIM card PINs, hence can use an arbitrary alphanumeric password (though l

But in the phone’s lockscreen, you are usually not bound by the 4-digit requirement of SIM card PINs, hence can use an arbitrary alphanumeric password (though likely rather short, as you have to enter it often on a small keyboard). 36^5 >> 10^4.