September 19, 2008:  Intelligence operatives (from infantry battalion intel analysts to their counterparts at the CIA) are becoming big fans of biometrics. That's a word that covers all those physical or behavioral characteristics that make individuals, or groups, unique. Soldiers, like police, are big fans of evidence, and the use of it to solve puzzles. Biometrics has, in the last decade, provided a lot more kinds of evidence.

The oldest biometric is your appearance, which is pretty unique. Next came fingerprints, which were first recognized as a biometric indicator four centuries ago, but did not become a feature of police work until 150 years ago. That was followed by blood types and a whole bunch of stuff you could only do with dead bodies. But in the past few decades, there's been a lot more. DNA, automated facial recognition, iris patterns and many more. But all this has been accompanied by new technologies that have made it easier to collect, store and retrieve biometric data. That made it possible to use biometric data on the battlefield. Al Qaeda was defeated in Iraq partly because of a huge (several hundred thousand individuals) biometric database, collected during raids or after arrest by U.S. troops. This took anonymity away from many terrorists, and potential terrorists or terrorist supporters. Made it much easier to run down the bad guys later.

But now behavioral biometrics is in play. This is using unique behaviors of people to identify them. The first one of these to get heavy use was typing patterns. Actually, this one was first discovered in the 19th century, when telegraph operators found they could recognize each other by the pattern each used when tapping the telegraph key. This was called an operators "chop", and was eventually applied to how people hit the keys on a typewriter, or computer keyboard. It was eventually found that everyone had a distinctive "chop" when using a computer keyboard, and software could be used to recognize individuals.

The availability of cheaper and higher resolution digital cameras made possible new biometric identifiers, like gait analysis (we each walk with a distinctive gait). This proved useful when using UAVs to look for elusive terrorists below. But it could also be used just as a surveillance tool. Of course you can deceive behavioral biometrics, but it isn't easy, and you're never sure that your change up has fooled the software.