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So you can't unlock your phone after coming from a plastic surgery? I always thought chances of finding facial-doppelgangers are higher than fingerprint ones.

So you can't unlock your phone after coming from a plastic surgery? I always thought chances of finding facial-doppelgangers are higher than fingerprint ones. Is that really wrong?

developer2 9y ago
You always have the password as backup to unlock. If your appearance were to suddenly change remarkably, such as via plastic surgery or a horrific accident, you would set your new face after unlocking with the password. Based on their phrasing, I'm assuming the "adaptive" aspect means that slow changes, such as gaining or losing weight, will progressively train the existing face - without it ever failing to recognize you because you passed some weight threshold. Same would go for growing a mustache or beard. As to whether you can shave off a 5-year beard and have it still recognize you without manual intervention, that would depend on how much the algorithm cares about your chin and lip regions vs. the rest of your face. Based on the demo, the hair on top of your head is 100% ignored.
mikeash 9y ago
Apple claims that the odds of a random person's finger unlocking your iPhone with Touch ID is 1 in 50,000, and the odds of a random person's face unlocking Face ID is 1 in 1,000,000.
- jandrese 9y ago
  I wonder what the odds are of someone unlocking your phone with a picture of your face? I've heard lots of biometrics companies say that their system is immune to such simple hacks in the past, only to immediately fall to such simple hacks in testing.
  - pls2halp 9y ago
    This time they’ve got an infrared sensore, as well as two cameras with different focal lengths, so they should be fine.
  - conception 9y ago
    I believe it uses an IR camera, or similar tech, defeat that, sensing depth. Kinect style. A photo won't defeat it.
- kurthr 9y ago
  That's interesting. I would think that identical twins would be very hard to distinguish... and those certainly have an almost 1:350 odds. Of course you're likely to know them, but still I'm not sure banks would be happy with that for FIDO.
  - suninwinter 9y ago
    They did say to not enable Face ID if you have an "evil" twin, which is pretty jokey, but probably 100% true.
  - threeseed 9y ago
    A twin could walk into any bank with their sibling's passport and do anything they wanted. Banks are all about risk management not necessarily avoiding and and all risks.
    - esolyt 9y ago
      But a twin wouldn't be able to unlock my iPhone 7 with their finerprint.
      - threeseed 9y ago
        You just disable FaceID in that scenario and go back to using a passcode. But again if you can't trust your twin well then your phone is the last thing I would be worried about.
  - mikeash 9y ago
    I think the number is if you choose another human at random, how likely is it that they'll be able to unlock your phone. Having a twin doesn't change that number much, since they're only one person out of 7+ billion. Of course, your threat model may be different from "pick a random human from anywhere on the planet."
  - hanspeter 9y ago
    > I would think that identical twins would be very hard to distinguish Ask their mom. (Hint: They're not.)

So you can't unlock your phone after coming from a plastic surgery? I always thought chances of finding facial-doppelgangers are higher than fingerprint ones. Is that really wrong?

developer2 9y ago

You always have the password as backup to unlock. If your appearance were to suddenly change remarkably, such as via plastic surgery or a horrific accident, you would set your new face after unlocking with the password. Based on their phrasing, I'm assuming the "adaptive" aspect means that slow changes, such as gaining or losing weight, will progressively train the existing face - without it ever failing to recognize you because you passed some weight threshold. Same would go for growing a mustache or beard. As to whether you can shave off a 5-year beard and have it still recognize you without manual intervention, that would depend on how much the algorithm cares about your chin and lip regions vs. the rest of your face. Based on the demo, the hair on top of your head is 100% ignored.

mikeash 9y ago

Apple claims that the odds of a random person's finger unlocking your iPhone with Touch ID is 1 in 50,000, and the odds of a random person's face unlocking Face ID is 1 in 1,000,000.

jandrese 9y ago
I wonder what the odds are of someone unlocking your phone with a picture of your face? I've heard lots of biometrics companies say that their system is immune to such simple hacks in the past, only to immediately fall to such simple hacks in testing.
- pls2halp 9y ago
  This time they’ve got an infrared sensore, as well as two cameras with different focal lengths, so they should be fine.
- conception 9y ago
  I believe it uses an IR camera, or similar tech, defeat that, sensing depth. Kinect style. A photo won't defeat it.
kurthr 9y ago
That's interesting. I would think that identical twins would be very hard to distinguish... and those certainly have an almost 1:350 odds. Of course you're likely to know them, but still I'm not sure banks would be happy with that for FIDO.
- suninwinter 9y ago
  They did say to not enable Face ID if you have an "evil" twin, which is pretty jokey, but probably 100% true.
- threeseed 9y ago
  A twin could walk into any bank with their sibling's passport and do anything they wanted. Banks are all about risk management not necessarily avoiding and and all risks.
  - esolyt 9y ago
    But a twin wouldn't be able to unlock my iPhone 7 with their finerprint.
    - threeseed 9y ago
      You just disable FaceID in that scenario and go back to using a passcode. But again if you can't trust your twin well then your phone is the last thing I would be worried about.
- mikeash 9y ago
  I think the number is if you choose another human at random, how likely is it that they'll be able to unlock your phone. Having a twin doesn't change that number much, since they're only one person out of 7+ billion. Of course, your threat model may be different from "pick a random human from anywhere on the planet."
- hanspeter 9y ago
  > I would think that identical twins would be very hard to distinguish Ask their mom. (Hint: They're not.)