That Thumbprint Thing on Your Phone Is Useless Now | Hacker News Reader

That Thumbprint Thing on Your Phone Is Useless Now

defenseone.com

29 pointsrbc21 comments

The one on my phone isn't useless now, because my fingerprint data wasn't stolen in the OPM breach (and nobody else has it either).

Even if my fingerprint data were out there, that doesn't really help get into my phone if it's casually stolen. The thief won't know who I am, so they won't know which fingerprint to try out of the millions of possibilities. They only get five attempts.

As always, you have to define your threat model. My phone's fingerprint reader protects me against common thieves. It also protects me against the authorities to a pretty large extent. As long as I have the opportunity to turn my phone off beforehand (I always do this when going through customs, for example) then the fingerprint no longer works to unlock my phone. The ease of use that the fingerprint reader provides for most usage allows me to have a much stronger password on the device than I would have otherwise, so I'm pretty sure it's a strong net gain.

It doesn't protect me against a determined adversary who targets me specifically, but then I already knew that. Fingerprint authentication is far from perfect, but it's not meant to be anything else.

You're plastering your fingerprints, aka "keys" over everything you touch. A sophisticated criminal could steal your pint glass and phone at an eatery when you're not looking. There's a chance they could pull your prints off the glass, recreate them on a substrate, and then unlock your phone.

https://xkcd.com/538/

Sure, but it's about a million times more likely that they won't bother with the fingerprints and will just sell my phone for parts.

Nobody is going to be lifting fingerprints off of pint glasses to unlock a phone unless they think there's something really valuable on that phone, and that means "a determined adversary who targets me specifically."

Don't keep nuclear bomb plans or thousands of bitcoin on your phone if you're going to protect it with your fingerprint. But mundane e-mails and such? Good enough for me.

No. This article is clickbait. Chinese hackers might have your fingerprint if you worked for the US government. But they don't have your phone. If you're a high value spy or something where the Chinese government is going to target you, steal your phone and match it with the fingerprint database you might be in trouble. Otherwise, the fingerprint+pin is still going to work great at keeping your significant other from seeing your flirty texts and your porn browsing history, or whatever.

It's like leaving your house key at a restaurant and someone saying all locks are now useless because someone might have your key.

I would probably change my locks

Somewhere here on HN I read that fingerprints are not passwords but user ids.

So your fingerprint authenticates you to provide your password.

Right now implementations are for fingerprints as passwords.

"Authenticates you to provide your password" meaning...?

The biometric reading is your user id, once the biometric reading process has been performed and the user determined the logon process would ask for the password corresponding to that user id.

I don't expect or want to type in my username every time I unlock my phone. Nor my secure alphanumeric password.

Usernames are easy to guess or find out, so in that scenario, the fingerprint scanner would go to waste unless you used a weird username.

It's unfortunate that so much emphasis has been placed on biometrics (especially fingerprints) as a security measure, more so because of their convenience which lulls users into a false sense of security.

Not only can biometrics not be changed, unlike a password, but they cannot be withheld from a would-be accessor in the way that a password can (until mind reading becomes a thing, that is).

I don't know how true this is, but it feels like biometric authentication for consumers has sucked the oxygen out of attempts to create convenient but secure authentication that doesn't have the same flaws (I don't know what a potential system would be, but there have to be better alternatives). Lazy reliance on biometrics will, I think, make us all a lot less secure.

I think people are figuring this out will and use biometrics as a second, or ideally third factor for authentication.

As far a bad authentication, this bothers me far less than when people (and this includes banks!) use my birthday, residence history, or other easily mine-able information to establish identity.

Another design pattern that makes little security sense is to email passwords in the clear in confirmation emails after signup

Hyperbole and extremism in info-sec publishing. Film at 11.

Fingerprints are a terrible form of authentication anyway. They're irrevocable, and you inherently leave copies of them everywhere just by touching things (unless you take special precautions). Same goes for DNA. Biometrics just aren't very good as shared secrets.

The title should read: "Thumbprint thing may be useless for authentication". There are other uses for it outside of security. I have a cydia tweak on my phone that will open different apps based on which finger I press to the home button.

Thumb/finger prints aren't useless for authentication, they just limited and shouldn't be used as the primary method. They can form a valid part of a security plan as they can protect against certain types of attacks with minimal intrusion.

This is the reason you should only ever use biometric data as a replacement for your Username - NEVER as a replacement for your Password!

I suppose the next step would be to see how hard it would be to lift a usable fingerprint from a stolen phone. Would that be good enough?

In other news - doors are useless! All someone has to do is steal your key and find your house.

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