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It is pretty bad that a colleague can unlock your phone, but they would also be able to see and remember your 4-6 number pincode to unlock your phone as well, e

It is pretty bad that a colleague can unlock your phone, but they would also be able to see and remember your 4-6 number pincode to unlock your phone as well, even touchId can be fooled by a person who happens to have a very similar fingerprint. I feel Apple should let your train the FaceID a bit more so that it is more correct, or maybe a setting on how precise the match should be, as this is a clear example of where the Face detection is too loose to ease the user compared to the lower security.

mikeash 9y ago
According to Apple, Touch ID is far more likely to fail in this way. They say the false positive rate is 1 in 50,000 per fingerprint, and you can enroll up to five fingerprints, so the chances could be as high as 1 in 10,000. Face ID is supposedly 1 in a million. That’s still high enough that we’d expect to see stories like this from time to time.
- RodgerTheGreat 9y ago
  No one can tell at a glance how similar two people's fingerprints might be, so finding a collision by accident is very hard. Finding similar-looking faces from a pool of candidates is, in contrast, very easy for humans. It would probably be even easier to find matches if we knew the precise heuristics Apple employs for ignoring glasses, headwear, facial hair, and so on; to be at all practical the feature must have generous degrees of freedom, which in turn reduce discrimination. Finally, as many have observed, there are plenty of situations where humans will be in close physical and social proximity to others with similar faces: twins, siblings, etc. Even if collisions are as infrequent as Apple claims (which I find dubious), face identification is fundamentally a lock that is easier to "pick" than fingerprints. I am forced to conclude that depending on facial recognition is a poor engineering decision motivated by user convenience whose limitations are deliberately mischaracterized by marketing materials.
  - mikeash 9y ago
    The main use case for a phone passcode is keeping your stuff secure in the event that it’s lost or stolen randomly. Both technologies are fairly secure against run-of-the-mill thieves. They’re good enough that the market for stolen phones is probably reduced to breaking them down and selling them for spare parts. If you happen to fall victim to a more sophisticated criminal, Touch ID is going to be way worse. Your phone is covered with the fingerprints needed to unlock it. It will take some sophistication to turn a print into something that can unlock the phone, but it’s doable. There’s no equivalent for Face ID. Most likely the criminal doesn’t know what you look like at all, so they could try five random people and then get locked out with a probability of success of roughly 1 in 200,000. If they know who you are they could try to look you up and find similar looking people, but that’s going to take time and effort and you have to get it done within 48 hours, and the odds of success are still not great. (If it was easy to reliably unlock the phone with a similar-looking person, we would have heard a hundred stories like this by now.) It’s far from perfect but I have no qualms trusting my security to it. It’s better than Touch ID and far better than the 0000 passcode I used before that.
- addicted 9y ago
  This completely ignores locality. As far as I am aware there is no reason to believe siblings or relatives should have similar fingerprints. On the other hand relatives are more likely to have similar facial features. So for the people who have regular access to your phone, there is no reason to believe the fingerprints should be similar. There is reason to believe their appearances would be.
  - mikeash 9y ago
    I bet the security is still pretty good even with similar-looking people. Otherwise we would have heard a lot more stories like this by now. In any case, I’m not trying to defend against my brother, I’m trying to defend against a random thief. They probably won’t look too much like me.
    - ggg9990 9y ago
      A lot of people are trying to defend against their family member much more than against a random criminal.
      - mikeash 9y ago
        Those people should consider a difference device, then, or only using a passcode.
    - lagadu 9y ago
      Depends on how you define "random" thief. Random as in someone taken randomly from anywhere on earth? Yeah, faceId is likely more secure. Is it random as in someone taken randomly from your city or country (which is the most likely scenario)? Then we're talking someone who is likely significantly closer genetically and in appearance to you, which greatly increases the odds of the thief being able to unlock the phone. In more isolated places like islands this effect is even more pronounced. On the other hand, fingerprints don't suffer from that effect, as they're unaffected by genetic diversity.
  - valuearb 9y ago
    Similar looking people can’t unlock an iphone X. These are almost all cases where the phone was trained to recognize both people.

mikeash 9y ago

According to Apple, Touch ID is far more likely to fail in this way. They say the false positive rate is 1 in 50,000 per fingerprint, and you can enroll up to five fingerprints, so the chances could be as high as 1 in 10,000. Face ID is supposedly 1 in a million. That’s still high enough that we’d expect to see stories like this from time to time.

RodgerTheGreat 9y ago
No one can tell at a glance how similar two people's fingerprints might be, so finding a collision by accident is very hard. Finding similar-looking faces from a pool of candidates is, in contrast, very easy for humans. It would probably be even easier to find matches if we knew the precise heuristics Apple employs for ignoring glasses, headwear, facial hair, and so on; to be at all practical the feature must have generous degrees of freedom, which in turn reduce discrimination. Finally, as many have observed, there are plenty of situations where humans will be in close physical and social proximity to others with similar faces: twins, siblings, etc. Even if collisions are as infrequent as Apple claims (which I find dubious), face identification is fundamentally a lock that is easier to "pick" than fingerprints. I am forced to conclude that depending on facial recognition is a poor engineering decision motivated by user convenience whose limitations are deliberately mischaracterized by marketing materials.
- mikeash 9y ago
  The main use case for a phone passcode is keeping your stuff secure in the event that it’s lost or stolen randomly. Both technologies are fairly secure against run-of-the-mill thieves. They’re good enough that the market for stolen phones is probably reduced to breaking them down and selling them for spare parts. If you happen to fall victim to a more sophisticated criminal, Touch ID is going to be way worse. Your phone is covered with the fingerprints needed to unlock it. It will take some sophistication to turn a print into something that can unlock the phone, but it’s doable. There’s no equivalent for Face ID. Most likely the criminal doesn’t know what you look like at all, so they could try five random people and then get locked out with a probability of success of roughly 1 in 200,000. If they know who you are they could try to look you up and find similar looking people, but that’s going to take time and effort and you have to get it done within 48 hours, and the odds of success are still not great. (If it was easy to reliably unlock the phone with a similar-looking person, we would have heard a hundred stories like this by now.) It’s far from perfect but I have no qualms trusting my security to it. It’s better than Touch ID and far better than the 0000 passcode I used before that.
addicted 9y ago
This completely ignores locality. As far as I am aware there is no reason to believe siblings or relatives should have similar fingerprints. On the other hand relatives are more likely to have similar facial features. So for the people who have regular access to your phone, there is no reason to believe the fingerprints should be similar. There is reason to believe their appearances would be.
- mikeash 9y ago
  I bet the security is still pretty good even with similar-looking people. Otherwise we would have heard a lot more stories like this by now. In any case, I’m not trying to defend against my brother, I’m trying to defend against a random thief. They probably won’t look too much like me.
  - ggg9990 9y ago
    A lot of people are trying to defend against their family member much more than against a random criminal.
    - mikeash 9y ago
      Those people should consider a difference device, then, or only using a passcode.
  - lagadu 9y ago
    Depends on how you define "random" thief. Random as in someone taken randomly from anywhere on earth? Yeah, faceId is likely more secure. Is it random as in someone taken randomly from your city or country (which is the most likely scenario)? Then we're talking someone who is likely significantly closer genetically and in appearance to you, which greatly increases the odds of the thief being able to unlock the phone. In more isolated places like islands this effect is even more pronounced. On the other hand, fingerprints don't suffer from that effect, as they're unaffected by genetic diversity.
- valuearb 9y ago
  Similar looking people can’t unlock an iphone X. These are almost all cases where the phone was trained to recognize both people.