Bruce Schneier Talks About Biometrics

What are biometrics?

A biometric is basically a physical attribute of yourself that's attached to your identity. So, a picture is a biometric. Your eye color is a biometric. More modern biometrics are finger prints, and retinal scans, maybe voice prints. But there's some way to match your physical person to an identity.

Some people think biometrics are a silver bullet for identification. True?

You know, biometrics will work in some circumstances. If you can verify the path between the biometric and the authenticator, it can work pretty well. So, for example, you have to use a biometric to get into CIA headquarters. And the reason they know that someone isn't using a rubber finger or a photograph of a finger or any of the other ways to cheat a fingerprint reader, is there's an armed Marine guard standing in front of the reader making sure the person is doing the system like they should. Any time you try to do biometrics remotely, there's no way to verify the path between the finger and the authenticator.

Should we put fingerprints on ID cards?

I don't like seeing more biometric information on ID cards. I like seeing a picture. That works real well. The problem with a fingerprint is a person can't verify it easily. You need equipment to verify a fingerprint. And that suddenly adds a lot more risk into the system. On top of that we're now building, if we do this, a fingerprint database of all Americans. And that has its own security risks. So there tradeoffs are there, and some biometrics are good; pictures are great; adding things like fingerprints you have to be real careful about.

What about DNA?

Well, again, you have your problems with verification. How do you verify someone's DNA. If I'm getting on an airplane, what's going to happen that verifies my DNA? How does that system work? How do we prevent abuses of that system?

Can biometrics increase identity theft?

What biometrics can do is make identity theft more valuable. As identity becomes more and more ubiquitous, stealing someone's identity becomes more and more valuable. And you may ask, how do you steal someone's DNA? You don't steal someone's DNA. You hack the database so their identity has your DNA. Or, you hack the authentication procedures so that your DNA can pass as theirs. Sometimes it's just as simple as changing a test—are they equal to are they not equal. And now you can pass as them. So it's not DNA that increases identity theft; it's a reliance on automatic authentication that makes identity theft more profitable, which makes it a bigger crime.

Do we have to increase security with biometrics?

Yeah, I'm not convinced we do. There are places we do, right. Banks. They have to make sure that when you come to take out the money that you're the same guy who brought the money in last week, right? And they do that. They do a real good job at that. It's real money to them. And they don't use biometrics. They don't even use pictures. They have an entire system to authenticate people that works for multimillion dollar transactions and works well. There are places you need identity, and in those places, we have systems that work. There are a lot of places you don't. And security is not identity. A lot of people think identity is how security works. But think about a door lock. A tall fence. A burglar alarm. A reinforced cockpit door on an aircraft. There's a lot security that has nothing to do with identity.