Under the hood, [bio]ID generates a one-time token with a signature that serves as a superior substitute to a password.
If your face or fingerprint don't happen to be around, you can always use the password for the same account to reset it. If you have legal concerns about being coerced into using a biometric system, you should disable it.
One of the problems "biometrics shouldn't be a password" is meant to expose, is that you can't reset a biometric if it leaks. By keeping the biometrics inside a device at all times, the T2 system substantially mitigates this risk. I'm fairly certain you can remove a device from your Apple account, and the ID system will no longer work, even if provided with your face or fingerprint.
Second, the primary threat identity providers (and their users) deal with are remote, impersonal hijacking of accounts, where the password is either guessed (because it existed in a leak) or the user was phished.
That's the primary value of something like this. Attacks where someone can lift your fingerprints or has your device are real but much much less common.
Think like this, when you go to visit your grandmother and knock on her door you don't have to provide a password. You don't have to provide anything, because the human brain is capable of determining your identity in less than a fraction of a second. This is why as soon as your grandmother opens the door she'll have a smile on her face and welcome you in. That IS biometrics. Now machines can do the same. It's the oldest and most secure form of authentication in human history.
1) A password is secret
2) You don't leave copies of it lying around everywhere
3) You can change it periodically
4) If discovered, it can't be traced back to you
No, biometrics can only be a username. It can never be an acceptable password.
Compare biometrics with identity:
1) Your identity is not secret. Your mother knows you, your entire school knows you, your neighbour knows you, when you go anywhere the police may ask for your ID at any time and knows you. Biometrics is the same.
2) You don't hide every day from the world. You don't cover your face (ok maybe before COVID) when entering a shop ;)
3) You cannot change who you are. You shouldn't have to and shouldn't want to. Same for biometrics.
4) If your identity is discovered then of course they know who you are. Same applies for biometrics.
So yes, biometrics isn't passwords, it's identity. Username + Password is a workaround to establish a person's identity and will never be as good as a biometric. The fact that you can have multiple usernames but only the same right index fingerprint is proof that biometrics is superior in establishing your identity than username + password.
This is just dogma, it's not based on the actual implementation details.
TouchID for the web requires: Something you are (biometric), and something you have (Your phone/ computer).
If someone "Discovers" my fingerprints, they are worthless without the phone/ computer which has the Secure Enclave I've matched them to. If my phone is stolen, I can invalidate the entire device as a method of authentication.
Websites are not receiving your biometrics in this context, and your biometrics would be meaningless to the website if captured and somehow provided.
Your biometric signature is stored solely inside the Secure Enclave in the Apple device.
If and only if the Secure Enclave recognizes you via your biometrics will the Enclave uses a non-transferrable key stored only in the Enclave to attest to the website that you are the user "JoeAltmaier".
- The key is secret.
- The key is kept in only one place.
- The key can easily be discarded and a new one made.
- The key is never given to anything outside of the Enclave, so... I'm not sure how it could be traced to you, besides the whole fact that it is being used to authenticate you, which is necessary.
Sounds pretty acceptable to me as a password. The usability issue here is that a website needs to be able to accept a different password from each device you own, since the password is non-transferrable, and you might accidentally drop your iPhone to the bottom of the ocean.
Good news: FIDO2 is an entire standard built around this concept, originally intended for use on YubiKeys and similar FIDO2-compliant USB sticks.
Apple is building an implementation of FIDO2 that uses the iPhone that's already in the person's hand.
If the Secure Enclave is compromised (which does happen sometimes), then Bad Things could happen... but that's also what happens when a password manager tool is compromised.
If someone wants to fake biometrics on an iPhone, they have a very limited window of time to do so, and the user can lock out the biometrics in less than 3 seconds just by "squeezing" the phone. (power button + either volume key, 2 seconds later the biometrics are locked out.)
It's much harder to fake the biometrics in that very brief window of time (maximum 48 hours) than it is to shoulder surf a password.
Unless your threat model includes State Level Actors, biometric bypass is a very remote concern.
If your threat model includes State Level Actors, you're probably screwed either way, since they can easily afford to shoulder surf you.
For everyone else, the main concern is that someone not physically present will manage to acquire your password and log into your services. Passwords suck at this threat model. FIDO2 makes this scenario impossible without that remote person managing to execute a Secure Enclave 0day on your personal device... and even then, it's still way harder than acquiring your password. Not even the website you're authenticating against receives your FIDO2 key... websites always receive your password, which is awful for security.
Some related info here: https://news.ycombinator.com/item?id=24830642
If biometrics are fallible, it matters zero how secure the digital system behind it is. That's obvious, and a comment belaboring the digital security is beside the point.
As for how hard to spoof, just google it. There are dozens of folks with techniques and hacks right now. It'll only get worse.
You cannot protect your passwords from someone who would physically take your iPhone before you can lock it and who would have a life-size reconstruction of your face ready and waiting. Such a person could shoulder surf your passwords with far less effort, or compromise one of the dozens of websites the average user re-uses their passwords on. At a certain point, the person in this threat model will just pull out a wrench and beat you with it until you help them get into your account. https://xkcd.com/538/
If you can show how some random person on the other side of the internet having your fingerprint helps them get into a website using your account... that would be interesting discussion. As it is, they must have physical access to your device. Your biometrics are useless without physical access and rapid action, since the biometrics quickly become useless as the device falls into a state that requires the user's passcode.
You're completely ignoring everything I actually said in my comments, so I'm done here.
It's also important to note that this does not mean anyone who grabs a laptop gets access to everything. The device still uses a password to unlock — you're forced to enter the password on boot before you can use biometrics later — and someone who stole an unlocked laptop could, for most users, have auto-fill supply the passwords _except_ on devices with biometrics which usually require that check every time (as iOS users have been reminded in this year of mask wearing).
So let's walk through some common threats:
1. Password re-use: a major source of compromises, blocked by this system 2. Phishing: a major source of compromises, completely blocked by this system 3. Compromised email: also popular, blocked by this system except for the services which allow email-based MFA resets, in which case it'd be the same as a password. 4. Local system compromise (user or root-level): passwords are vulnerable, biometrics present a barrier when the attacker can't just do something like reuse the credentials stored in your browser's cookie store. Biometric data and FIDO keys cannot be extracted. 5. Stolen device, locked: both are probably secure as long as you don't have your password taped on the keyboard 6. Stolen device, unlocked: passwords are vulnerable if you have a password manager which doesn't require e.g. FaceID checks (which is what Safari does on supported devices), FIDO MFA is not usable if Touch ID or Face ID is configured. Biometric data and FIDO keys cannot be extracted.
1. https://support.apple.com/guide/security/secure-enclave-over...
This app linked above (my bank) contains NONE of the security you've mentioned above.
And, incidentally, for me, biometrics STILL fail every test that matters to me: If I am dead, a bad actor can still gain access to my accounts. With a password, they cannot.
[0] https://apps.apple.com/us/app/bbva-m%C3%A9xico-bancomer-m%C3...
This misunderstanding is where you went wrong: your bank doesn’t have a choice about this. If they use FaceID, they don’t have a choice about implementing that - the app can ask it to perform the public-key authentication operation but there’s no way for the developer to choose to weaken the security of the system.
Similarly, you should read up about how these systems incorporate liveness checks. A dead body will not pass those and, if you weren’t aware, Apple’s implementation requires a password after a reboot or a small number of failed tries. It’s presumably possible for a well-resourced attacker to bypass those but you’d have to think about how much more vulnerable you are if you use only a password which is much easier for an attacker with that level of resources to capture. If you’re worried about Tom Cruise recording a mask from your still-cooling body, think about how much easier it’d be to get a camera to record you entering it - which you do a lot more in public if you don’t use biometrics - and how trivially this could be done without your knowledge.
This bank is NOT using FaceID, they invented their own version and are calling it the same thing. Your picture goes to their servers. Who knows what happens after that. And they're piggy backing on Apple's trust where FaceID is concerned in order to do it.
They are not the only company I have seen do this.
If your view of fingerprint auth is "a picture of your face is the password" then of course it sounds stupid. It's actually "a face with the correct features attached to an alive human" which is much harder to fake.
The whole point of biometric auth and all the advancements in the industry are about correctly identifying alive humans and the strength of any system that uses biometrics is directly related to that. You can say current systems aren't good enough at this yet for your personal thread models but it's real security, and beats the hell out of a 4/5 digit lock screen passcode.
And so far, biometrics falls far short of a 4/5 digit lock passcode. The entropy in most fingerprint sensors is a few bits. They are famously defeatable.
Nothing will change the fact that you cannot keep your face and fingerprints secret, cannot/won't change them, and they are always, always traceable to you. Using them to secure a 'better' key is not security at all.
Take this to meatspace for a second. If you had a security guard sitting at a desk inspecting your hands and taking fingerprints you couldn't trick them with pictures. You can't hold up a picture of my face to a guard and expect that they'll suddenly think you're me. Biometric auth systems are trying to the same thing but without the human.
> They are famously defeatable.
And most locks in wide-use today are also defeatable by amateur locksmiths, that's not really the point. There are sophisticated biometric auth systems that aren't fooled by pictures. FaceID is one example.
That means that you're left with really unusual situations like someone stalking you with drones with 3-D infrared scanners who can't figure out how to have the same drone record your password when you type it in many times per day.
1. https://support.apple.com/en-us/HT204587 https://support.apple.com/en-us/HT208108
Biometrics are closer to a public key than a password.
What you’re describing is essentially using a fingerprint instead of a private key or password for logging into a server via ssh.
The way this works is more akin to using a private key to login via SSH, but that private key is protected by a fingerprint instead of a password.
Ultimately the security comes from not sharing your private key, rather than the mechanism used to protect that key.
It's straightforward to configure Active Directory / Group Policy to require biometric and password factors for interactive authentication.
The main reason not to allow _only_ biometrics is to disincentivize chopping fingers off (well, it's more because [it's still surprisingly easy to fool biometric systems](https://www.theguardian.com/technology/2014/dec/30/hacker-fa...)).
There are extremely high-security biometric auth systems that you would have a much harder time fooling. The high-res retina scanners that take a 3d map of your eye and detect blood flow would be a much better assessment of what's possible.
I'm not sure what the UX is when moving devices though.
If the machine can prove that you are indeed you through biometric authentication, why take another step for authorization?