Can't put your finger on it

The recent example of winsome personal diplomacy performed for Brazilian airport security workers by an American Airlines pilot has given me an idea about how to overcome a persistent obstacle to biometric adoption.  Many of the arguments often made against fingerprint biometric authentication are misinformed and readily corrected, but one objection has been almost intractable.  Until just now.

The accuracy problem associated with false-positive and false-negative results is a real challenge for forensic and surveillance applications, because these kinds of uses require each individual scan to be compared against thousands or millions of stored records.  Picking a small group of individuals out of a large pool of people by briefly examining parts of their bodies is hard.  Smart people are working on it.  I’m glad it’s not me. 

However, for authentication (proving that you are who you say you are) you only have to match your fingerprint against one template (allegedly your own) stored on a reliable card or other credential.  False-positives are greatly diminished and false-negative errors only cause a minor inconvenience (just scan that finger again).  Privacy and cost concerns are similarly addressed – you can prove that you are who you say you are while preserving appropriate anonymity.  A good match-on-card or match-on-reader system combined with a reasonably secure and affordable storage medium and real-time validation is a pretty fast, accurate, private and affordable way to do strong authentication.  So what’s the big problem for wide-scale public deployments?

Shame.

Deep-seated psychological connotations found in many cultures equate getting your fingerprints taken with being accused of a crime.  Most people don’t like being treated like criminals.  Particularly high-minded ones may even be insulted by the perceived insinuation.  Put Queen Elizabeth and Joe Lieberman in an airport line and see how long it’ll take them to clear security (and don’t count on face recognition to tell them apart).  Changing this mindset will take a lot of patience and training - for the security professionals administrating the scans, not the finger-owners.  Here’s a shortcut:

Instead of scanning the index finger or thumb, go for the intermediate digit.  I propose that all new biometric scanners at public facilities be configured to accept the longest and most expressive of the fingers.  Reasonable and dignified security experts (such as myself) will present our fingers without comment, but people with an innate distrust of technology or law enforcement will be so giddy from having the chance to flip the bird at authority that they’ll line up for a second run through the scanner.

Of course that still leaves Senator Lieberman, but we’ve narrowed down the search space.