That isn't how skin works. Surely you've suffered the inconvenience of a small paper cut or kitchen knife nick on your unlocking finger. Even if you cut large

That isn't how skin works. Surely you've suffered the inconvenience of a small paper cut or kitchen knife nick on your unlocking finger. Even if you cut large enough to create a scar, you'd just re-register the new print and you're (allegedly) vulnerable to this attack again.