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Unhashable: Why Fingerprints Are Weaker Security Than Passwords (hackaday.com)
szczys writes: Fingerprints aren't terribly secure; you leave them on almost everything you touch. Many people won't realize that fingerprints can be captured and reproduced from casual photographs. It's actually worse than that. The very method with which fingerprints are stored is much weaker than passwords. Fingerprints cannot be hashed. By their very nature, each read of your fingerprint will be a little different, which breaks the hashing method. They can only be stored using encryption, which requires the same master password each time a new print read is compared to the stored key — a much weaker method than salted hashes. This more easily opens fingerprint credentials up to theft and brute forcing.
Using a fingerprint for authentication is like using one unchangable password for every system. Bad practice!
It doesn't have to be like this. All we need to do is make sure we keep talking.
They aren't some super secret thing you try to keep secret from everybody. You not just leak your DNA everywhere, you leak your fingerprints too. And unlike passwords, you can't just simply change them.
Your palm print or retina scan would have the same limitations.
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Am I the only one who immediately thought of amputation?
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The question isn't "is a fingerprint more secure than a password", it's "is a fingerprint more secure than no security". Most phone users didn't have any password on their device. Adding a fingerprint secured those devices.
Fingerprints, in fact all biometrics, are not passwords -- they are usernames.
In the 'perfect' security combination of { something you are, something you know, something you have }, they are the "something you are" part.
Is that actually true, though? I thought law enforcement, at least, identified fingerprints via a series of distinctive "features" rather than a full image of the fingerprint. In theory, couldn't these features be listed as to their presence/absence and coordinates relative to the center of the fingerprint, creating a consistent hashable value?
.. you can change a password once it is compromised, but you cannot change your fingerprints.
I say this because I wonder whether there's a way for scientists to read a password from my memory. I doubt! I have one that consists of a special combination of my school registration numbers since grade 9. Unbeatable!
To this sequence, I have added space, special keyboard characters from those number keys. It has worked for me for 21 years so far. One password of mine had 31 characters. All from my mind! No wonder the NSA can't beat this approach.
It's more awkward to hash a fingerprint than a password, sure, but it's certainly not impossible. An image of a fingerprint is mutable and "analog" feeling, but you could, instead, base your fingerprint comparison on a more "digital" digest of information from that fingerprint (eg. you boil image data down to bits that are repeatable in the face of repeated scans, like you check whether feature X is significantly more prevalent than feature Y in this print).
It'd be tricky, sure, and potentially impractical given current scan quality - but non-hashability is not some inherent limitation of fingerprints or biometrics in general.
Let's not stir that bag of worms...
This is an area that has seen quite a bit of research and there are ways to hash fingerprints. I little google searching led to Fuzzy Extractors which create a cryptographic key from biometric data and Fuzzy Vaults that store fingerprints in a secure way.
https://en.wikipedia.org/wiki/...
http://www.cse.buffalo.edu/tec...
https://eprint.iacr.org/2004/0...
The whole suggestion that fingerprints cannot be hashed or are unhashable is rather preposterous. The author points out that a tiny flaw in a fingerprint can result in the hash being different, and he may very well be right that that happens, but that's an implementation issue, not an inherent problem with hashing fingerprints. After all, if you're doing things properly, you won't be hashing the raw raster scan of the fingerprint itself, but rather a normalized/filtered vectorization of the fingerprint that can be trained to ignore slight discrepancies like those.
Will it be perfect? Nope. Will it allow for mismatches (i.e. hash collisions)? Absolutely, but if you implement your normalization/filtering properly the hash collisions should only occur once in a blue moon, just the same as they do with normal passwords (e.g. Apple says the chances of a random match are 1 in 50,000 with Touch ID; see page 8 of their iOS Security document).
When you get down to it, this problem isn't much different from how YouTube or Shazam do their content matching, namely, they can take some sort of noisy data, apply a set of filters, generate a hash/fingerprint of the relevant data, then do a quick search based on that hash, rather than trying to actually match the noise in the coffee shop I'm in against the millions of tracks they've sampled. There are differences between those problems and this one, to be sure, and simply encrypting the fingerprint instead of hashing it does make things a LOT easier to implement (e.g. Apple doesn't hash fingerprints, but they do take the extra step of discarding minute details that would be necessary to reproduce a fingerprint before they encrypt it for later use), but to suggest that fingerprints are unhashable just seems silly. We're in the early days of fingerprint scanners in widespread use, and I'd expect that things will head in that direction with time.
Just pre-process them with something like SIFT to eliminate the variations introduced from one reading to the next and hash that.
I always think of this scene when I hear about biometrics....
http://cdn.av.s3.amazonaws.com/wp-content/uploads/2013/07/15142727/Wesley-Snipes-eyeball.jpg
fingerprints and retina scans are more like usernames, not passwords. Just another way to verify that you are who you are. The password is still necessary to get access.
I can also extract a cryptographic code from a fingerprint, and it can be revoked and a new one made.
I know this sounds impossible, and nobody but me seems to have made a good system for this.
Probably because the math is quite tricky and unpublished.
Someone forgot to tell Apple that they're not hashable... because that's how they're storing them.
But then, you don't use them as a key to encrypt, you use them to *verify* that you are you. This takes care of dumb people trying to break into your phone. The smart ones just open up the phone and try to read the flash and security EEPROM directly.
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$Stalag99{"URL"}="http://stalag99.net";
Just ask the FBI if fingerprints can be hashed. They've been doing it for decades as part of AFIS - the Automated Fingerpritn Identification System.
In a nutshell: Software looks for minutae in the print - locations of whorls, loops, valleys, etc. Once those are located it decides where they are relative to each year, then puts those relative coordinates into bins. The smaller the bins, the less tolerance there is for variability like being squished hard against the scanner and spread out. If you set your bins too small then you'll get a bunch of false negatives. But you don't have to do just one set of bins - you can do multiple bins, progressively more precise and then put them in a search tree where the further you go down the tree the more confidence you have that the print is a match.
Those bins are effectively a password which can be hashed just like any other password and you can store hashed bins instead of originals in the clear if you want because you are just doing a bit comparison with each higher level of precision.
I think people who come up with this stuff watch too many movies where its so cool to have facial recognition or fingerprint security. How about retina next?
If you have a stagnant security system then someone has the ability to hack it. At least with passwords you have the ability to change it and if you do it with a reasonably good one it then makes that stagnant security fluid and ever changing. Which makes the hackers cringe. I totally agree fingerprint authorization is about as worthless as a 4 digit pin.
As some others pointed out, you leave your fingerprints everywhere, making it a very bad authentication method. Damn, imagine someone breaking into one of your accounts just because you tossed your used cup of coffee in a public bin...
Most match protocols use point algorithms to store the points and patterns.
The fact that you've never seen this does not mean we don't have it. We just don't tell you.
However, all biometrics are highly hackable. Including and especially facial recognition.
The chief way to stop people is to pay attention to your actual vulnerabilities and concentrate on those, and vary the more easily defeated protocols.
Stop believing movies. Most of what you see in those are fake.
-- Tigger warning: This post may contain tiggers! --
I assume Theft refers to someone cutting off your thumb and Brute Forcing refers to a brute putting you in a headlock while his partner forces your thumb onto the sensor.
We keep talking about passwords as if they were some magical key. They're not. They're no different, on a theoretical basis, than a unique physical token or a unique biometric - it's simply a means for you to verify WHO YOU ARE. There are no passwords, only versions of usernames.
Yes, fingerprints can be copied. As can usernames. Tokens can be stolen. Passwords can be beaten out of you (and I use beaten in a general sense, not necessarily a physical one). Using two of those will prove to be rather difficult to circumvent on a properly created challenge system without the enduser's knowledge. Getting to someone's data by using their login and password (or biometric equivalent) is rarely the easy way; it's often simpler to break the backend or intercept the data in transit.
Is it just my observation, or are there way too many stupid people in the world?
You can, at least, refuse to divulge your passwords.
File under 'M' for 'Manic ranting'
Are they claiming that homomorphic encryption is impossible? This was an open problem for a long time, but the Ishai-Paskin cryptosystem is supposed to be a solution. Is there a flaw in it?
You can, at least, refuse to divulge your passwords.
Sure, but then you're pretty much leaving yourself to this:
http://www.explainxkcd.com/wik...
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Seriously, you are laboring under the delusion that it's hard to get a finger print or come up with a way to fool the sensor reading the finger print. You literally leave finger prints EVERYWHERE you go and like it or not, most scanners in use these days are chuck full of compromises on things like not looking at the whole print or they don't save enough detail but condense down your print into some mathematical expression. Not to mention that if you ever are able to break into a system that accepts fingerprints and obtain this data, you can easily construct a way to "fake" the system so they don't need access to you, ever.
Like all security ideas, it sounds great on paper, but when you start looking at the details of how it all works, the wheels quickly come off the train because doing it the right way is too hard, too expensive or too inconvenient to be useful. Most Fingerprint bio-metric based access control schemes fail in some way because of the implementation issues, they get compromised because they are expensive, or start to loosen the acceptable standards for a match because users complain of too many rejections.
Fingerprints just look like they'd be secure but as implemented they just don't turn out to be all that secure.
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This sounds like an ideal job for homomorphic encryption. Compare a sample to a fingerprint without ever revealing the sample or the fingerprint to a third party.
Some drink at the fountain of knowledge. Others just gargle.
You can lift fingerprints from photos. Photos can be accessed remotely by people you have no contact with.
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I am so tired of this over-hashed argument (see what I did there?). Fingerprints are not meant to be passwords, they are *secure usernames*. In other words they provide a username that no one knows or can figure out. As such they provide some security, but not to the degree of a good secret password. So by itself a fingerprint shouldn't be used for security. But, a fingerprint makes a good part of a multi-part system. In most cases a fingerprint and a pin is quite sufficient and much better than a known or obvious username and a typically poor secret password. P.S. Inferred handscans are even more secure than fingerprints, and given all the issues with passwords, are probably sufficient in themselves in most cases.
The large vulnerability is not in the encryption of the stored fingerprint information. It's in the very poor tools for measuring and reporting valid fingerprints, which allow matching with even vaguely similar fingerprint images. The original infamous study on the problem is at http://web.mit.edu/6.857/OldSt..., and there was even a MythBusters episode demonstrating the essential vulnerability of the system to casually sampled, stored, and replicated fingerprints at https://www.youtube.com/watch?... .
It was especially impressive that Mythbusters used a printed copy of a fingerprint, licked it, put it on the commercial biometric scanner, and were able to defeat the security scanner. These devices are security theater at its worst.
Finally, a slashdot topic where I can be informative. Disclaimer: I work in the industry building fingerprint sensors.
Fingerprints aren't perfect security. As so many others have pointed out, you leave them everywhere. That doesn't mean that they're not useful.
1. It's extraordinarily difficult to create a fingerprint spoof from a latent print. Yes, there are people who can do it - I can do it - but it's not easy. Notice on the videos of breaking into the iPhone 5s or 6 that latent prints are taken from a single fingerprint placed carefully on a squeaky clean screen. On your average phone, not so much. Someone who picks up my phone off the seat in a subway will be incapable of breaking in - unless I've just cleaned the screen with windex and carefully placed my fingerprint on it.
2. A fingerprint on a phone makes an excellent two-factor authentication system. The average hacker in east Elbonia can't break fingerprint security - because they don't have my phone or my fingerprint.
Perfect? No, but strong? Yes.
And the worms ate into his brain.
They can only be stored using encryption, which requires the same master password each time a new print read is compared to the stored key — a much weaker method than salted hashes.
You're doin' it wrong.
Most people aren't worried about some sophisticated attacker that is performing a targeted attack involving extracting fingerprints from pictures or surfaces, stealing your phone, and finding someway to physically enter the extracted fingerprint. Furthermore, phones that have fingerprint authentication drop the encryption key that's backed by the fingerprint on reboot and after a certain amount of time since last unlock (48 hours on the iPhone, but might be configurable). Then you need the password to login or read the data on the device. So an attack would have to steal the phone and successfully perform the attack within that time. For almost all users, that's more than secure enough and incredibly convenient.
I'm a nailbiter and it's common for nailbiters to not just bite their nails, but also bite the skin around their nails. I bite the skin on my thumb so I'm sure I'd have problems if I ever use a fingerprint scanner.
not to mention the ISIS type problems....
Fingerprints cannot be changed, and claim your identity - so they are a username. They can cannot be kept secret, and can easily be copied off a glass - so they are not a password.
Anything that can be recognized automatically can be also hashed by hashing the parameters used for recognition rather than the image they're extracted from.
I'm reminded of the Bond movie where he scans the fingerprint using his cell phone, then turns it around uses the scanned fingerprint to access the lock.
Your fingerprints are likely on there somewhere, and if someone really wants your print and device and you are careful they'll likely follow you and wait for you to leave something behind that'll give a great print.
Are you REALLY worried about that? Seriously? Anyone that serious about getting the contents of your phone is probably going to just grab you and put your finger on the reader.
Fingerprints are a shit security measure.
Maybe if you are worried about the Impossible Missions Force. In my case they work just fine. It's kind of like the lock on my house. No, it won't keep a determined intruder out but it will keep out casual snoopers.
. Fingerprints cannot be hashed.
Bollocks. Utter bollocks. I admit I didn't read TFA, but this is just bollocks. If a biometric system can identify what seems to be a fingertip (the presentation of which changes every time due to sweat, scars, position of the finger, whatever), it means that system originally stored a model that can match all possible (and reasonable) presentations of said fingerprint. If there is a standard model for representing a fingertip, then you hash that. That is your hash. It might be specific to the system using the "model", and thus incompatible with another system using different models. But this wouldn't be different from a system requiring SHA-512 hashes vs another one that requires MD5.
Mine change all the time. Fingerprint readers hate me, and I hate them.
But see, I actually do manual activities more demanding than typing, so I'm not the target demographic for fingerprint readers. The target's the wealthiest 20% (a group that includes almost 80% of the US population, since most of us no longer do real physical work, we just shuffle words).
When I lost the very tip of my right index finger it took six months to heal, and now it has a completely new print, mostly made of scar tissue. Works for everything except fingerprint readers!
This is not true. Extracted fingerprint templates can be hashed. It is also possible to create modified templates using a transformation function and thanks to this, create "cancelable" fingerprint credentials.
biometric feature cannot be the password, only the login. is this still open for discussion ?
I used to work in biometrics, and I am very sceptical of the idea that fingers can be reproduced from photographs. Even with training and willing subjects, it is not guaranteed that you will get a good fingerprint. I can't imagine a random photograph having enough detail of a finger to get a usable print. Maybe someone has this technology, but it is definitely not widespread.
No, they should not be used as usernames! We don't want facebook-like big brother stuff where every moron uses their real names for usernames just to discuss trivial stuff with his buddies.
I read the hackaday article yesterday, and it's missing one vital piece of information: WHY can fingerprints not be hashed?
It simply states they cannot, which sounds like bullshit.
Anything digital can be hashed. You can hash a txt file, you can hash an image.
Admittedly, my knowledge of fingerprint matching is limited to what they show on TV, as in "points of identification" or something, so why can't the "points of identification" be hashed?
Finger vein recognition is the answer. almost all of the objections of getting spoofed.
Imagine that you had a password for everything, and it was known to be stolen or broken. And, that you could not ever change it!!
However, they can be used -with- a password and be better than just a password by it's self.