> That's the entire point. It's a piece of information that even when it's known by everyone still can't be reproduced.

And yet, it can be reproduced. So it seems like the entire point is... invalid.

Produce me a living breathing human with a chosen fingerprint -- biometrics are not "a picture of your fingerprint is the password."

But similar to hash collisions, a total break (arbitrary hash values can be output) isn't required for it to be a problem. Where fingerprint scanners aren't magic (especially given the sloppiness of input data), that they're defeatable in corner cases should be enough to be worrisome.

Right but exactly like hashing you can set the difficulty of breaking it to your risk tolerance.

Your phone should probably be a little loose but the retina scanner at the datacenter of the dod will be a lot stricter.

That’s not a thing (Re: dod)

Not sure about DoD specifically but many datacenters absolutely employ retina scanners, LG makes a very popular line of them.

> Biometric security (i.e something you are) does not need to be secret nor revoked. That's the entire point. It's a piece of information that even when it's known by everyone still can't be reproduced.

If that's the point, the effort is doomed. All biometrics will be able to be reproduced sooner or later. There's no way around that.

So, like all other identifiers, revocation is an important trait. Even if successful reproduction is difficult and rare, it would be utterly devastating to those affected unless there's a way to revoke.

> Perfect: A human guard manually taking a fingerprint reading. Can't be beat because the guard can obviously see that it's not really your hand.

Not at all perfect. Can that human guard really see if you're wearing a fake fingerprint? I doubt it, unless he's closely examining everyone's fingerprints first. And even then...

>Not at all perfect. Can that human guard really see if you're wearing a fake fingerprint? I doubt it, unless he's closely examining everyone's fingerprints first. And even then...

The procedure at the USCIS to get my green card was remarkably thorough. The guard manually and visually checked each of my fingertips carefully to ensure I had no fake print overlayed on top of my real print and I had to keep my hands within a small area with a camera on it for the entire process or they would restart everything.

> If that's the point, the effort is doomed. All biometrics will be able to be reproduced sooner or later. There's no way around that.

All encryption will eventually be broken therefore what’s the point is a pretty bad security posture. But like no it won’t. Even if you can fake every other metric (good luck with eyes) a fresh blood sample taken by a guard with hypothetical futuristic instant DNA sequencing will never be broken. If your threat model is someone cloning you, the you have bigger problems and they still can’t clone your fingerprints!

You’ve got revocation completely ass-backwards. If someone successfully tricks a biometric system you don’t need to revoke someone’s fingerprint, you revoke the reader! That’s the thing that actually provides all the security.

The point of the guard is that a human has absolutely no trouble determining whether they’re taking a reading of a real hand, scanning a real eyeball, to taking a real blood sample. Maybe in mission impossible movies but you’re really really overstating the resources required to make a convincing hand to someone specifically looking for fakes. Yes social engineering is a problem which is why an autonomous system with the detection quality of a human would be nigh unbeatable.

Alright, but then passwords are on the table again in my opinion. There is no need for a system to identify me in the vast majority of cases that would not be sufficiently proved by my secret knowledge, which is harder to replicate than any biometric marker.

> All encryption will eventually be broken therefore what’s the point is a pretty bad security posture.

When a given crypto scheme is broken, you can change to one that isn't. When your physicality is compromised, you can't change to a new body.

Furthermore, that guard can be incapacitated, or easier still, bribed.

My thought is that biometrics should be the root of identity, not the endpoint. You shouldn't need to scan your retina, fingerprint, or face at every point you want to verify your identity. Instead you use other things like public key cryptography to verify your identity remotely, id cards (perhaps with strong cryptography) for in-person interactions, etc.

Lost/stolen cryptographic keys or ID cards could be revoked and would require a trip to your a certified biometric verification facility where a thorough in-person inspection would confirm that your fingerprints are real, you aren't using a fake eye, etc. Then you'd be issued new keys/cards at that location. Loss of ID is inconvenient, but not catastrophic. Leaking your biometrics is irrelevant.

Is it an infallible system? Certainly not, but it should be able to uniquely identify someone and not allow faking biometrics.

It isn't that relevant if is infallible if you don't need it in the first place. What would the purpose be? Checks by authority? Not too convincing to be honest.

> biometric verification facility

sounds expensive.

>- Perfect: A human guard manually taking a fingerprint reading. Can't be beat because the guard can obviously see that it's not really your hand.

"Perfect" is too strong a statement. This is only true if the guard very carefully checks every fingertip to ensure nothing is glued over your normal fingertips, and even then it's possible to distract the guard or rush them with a socially-engineered premise. Or just bribe or blackmail them.

You’re missing the point.

Biometrics are not the weakness. Current implementations are.

> Perfect: A human guard manually taking a fingerprint reading. Can't be beat because the guard can obviously see that it's not really your hand.

Well, the argument some people are making is that this might be no better than a human checking your ID. Yes, there the guard can verify that there is some real human there, but both the ID and the fingerprint could be faked (e.g. a fake fingertip mold which matches the victim's "known" fingerprint).

We're talking about a guard who physically takes your hand, inspects it, and puts your finger in ink, and then compares that to the prints they have on file. This is exactly the protocol that's used by the police and military when taking prints.

So wear fingerless gloves and social engineer a little bit (it's cold, it's winter, I have bad circulation, etc). If you think having a human guard makes a system infallible, I have some bad news for you.

Oh lord, this is firmly off that point. An alert motivated human looking for fakes can identify them with nigh perfect accuracy. This means that it should be possible to build an autonomous system that can do the same which is the goal of biometric auth systems. There is nothing that fundamentally breaks biometric auth until you can burn fingerprints on someone or replace eyes or gene therapy new DNA or whatever. And even then that’s pretty damn strong.

Exactly, every keeps going on about magic social engineering attacks without providing details.

Anyone who has had their fingerprints taken by the FBI knows that there is a solid procedure that will detect fakes. The idea is to replicate this near perfection, not bolt on some revocation system for fingerprints (ouch!)