Steal my ID, steal my fingers - the public gets nervous

So how many fingers do you need anyway?

The public fears losing their fingers to ruthless biometric ID thieves in the fingerprint-controlled future, apparently. Or at least, so says Frost & Sullivan analyst Sapna Capoor, who argued unconvincingly that "A dead finger is no good to a thief."

If you have a fingerprint scanner protecting your family jewels, your data might be safe, but what about your fingers?

So, it's all getting out of hand? Then on the other... there are recorded instances of people having their fingers chopped off, and the biometric industry takes the issue seriously.

For example, there were the Malaysian crooks who nabbed a man's fingers in order to operate the biometric security on the S-class Mercedes they stole from him.

Nevertheless, biometric firms are doing what they can to detect whether a fingerprint being scanned is alive or not, said Jean Francois Mainguet, chief scientist of fingerchip biometrics at Atmel-France, and inventor of the sweeping technique for direct silicon fingerprint scanning (he was awarded his patent on 9/11, as it happens).

Speaking at Biometrics 2006 in London, Mainguet said it wasn't yet possible to detect "liveliness", and even when it was, this would guarantee security no more than a regular biometric.

"Absolute security doesn't exist," he said. If you could detect liveliness, you wouldn't be able to tell if someone was accessing some system or authorising some payment under duress or not.

Security causes an escalation of causes and reactions just like the arms race. Want to cheat the banking system? Forge an ID. Fingerprint scanner making it tricky? Chop someone's finger off. Live fingerprint scanner? Hold someone's family at gun point.

The techniques being explored for live scanners include inducing involuntary responses via an electric charge to cause a spasm in skin pressed against the glass. Or there's the use of light fluctuations to induce involuntary responses from the user of an iris scanner.

They can all be faked, said Mainguet. The electrical response, for example is as easy as making a frog's leg twitch if you have chopped carefully.

There is a solution, he said, which is to use a variety of biometrics to identify someone. Biometrics? You just can't get enough of them. At some shows, anyway. ®