4 ms·
I think that this would be easily detectable by testing capacitance. The steel ring around the home button could potentially be used for that.
by trebor 13y ago
I think that this would be easily detectable by testing capacitance. The steel ring around the home button could potentially be used for that.
- option_greek 13y agoI do hope that the one removing the finger knows that.
- joezydeco 13y agoCapacitive sensing doesn't detect if a finger is alive or not.
- georgemcbay 13y agoA dead finger is the same as a live one as far as capacitance goes unless it has been dead so long that all the moisture is gone, in which case you could just dip it in water prior to the scan. Having said that, the idea of losing a finger to access the device doesn't really make much sense. You've got to incapacitate someone pretty well to take their finger off, so you might as well just force them to touch the phone while they are so incapacitated, unless you really like chopping off fingers.
- trebor 13y agoHumans are pretty powerful conductors, are you sure that a sensitive capacitance sensor couldn't tell the difference between a finger and a finger attached to a body? I don't know it for a fact, but I'd be surprised if not.
- georgemcbay 13y agoA garden variety capacitive sensor can't tell the difference between a human finger and a hot dog. How do you propose it would beyond attempting to measure the amount of capacitance and mapping it to an accepted band? Attempting that is way too fragile a solution due to variability in humans and local weather conditions. And even if you did put in the effort for that, an attacker could still fairly easily match the dead finger capacitance to the correct band pretty easily.