Ambient noise is another problem, especially if you are outside on a tarmac, inside a client's office, or in a classroom full of kids. Or, in my case, standing in the rain, trying to get the voiceprint lock to open between thunderclaps. Striations in the eye's iris are a thousand times more distinctive than the whorls on a finger, so in principle iris prints should be even more reliable than fingerprints. In 1995, the first iris scanners were successfully deployed to provide security for prison doors and bank vaults, says Lou Sassano, vice president of worldwide sales for IriScan, a New Jersey company that holds patents on the technology. Bank United of Texas recently set up three automatic teller machines equipped with IriScan's technology in Dallas.
Facial recognition is prone to error but is even more stealthy.
Viisage Technology, a Massachusetts firm, has developed a system that would allow police to scan a driver after they stop a vehicle. Their approach, based on technology developed at the Massachusetts Institute of Technology Media Lab in the early 1990s, would use a hidden camera on the officer's collar to photograph people in the car. Then a pair of radios would transmit the image to the police station, where a computer would run a comparison against a face-recognition database and transmit an alert to the officer if the driver were wanted or dangerous. Another Viisage product, called Hunter, is designed to pick out known terrorists from airport surveillance cameras. More than 50 casinos already use a similar system of hidden video cameras and computers to identify known scam artists and cardsharps.