Palm Vein ID Scan Makes U.S. Debut

Aug. 18, 2008 -- Palm vein scans are about to make their American debut. Used in Japanese automated teller machines for more than five years, the Graduate Management Admission Council (GMAC) recently announced that by next year all students who want to attend business school will be required to take a palm vein scan to verify their identity.

"It's easy to steal a fingerprint," said Hiroko Naito, a member of Fujitsu's PalmSecure Team that developed the technology. "Palm vein information physically resides inside the patient, making it harder to steal."

The palm scans are designed to thwart proxy test taking, a scam where an applicant pays someone else (the proxy) to take the test for them so they can get a higher score than they otherwise would. The palm vein scans wouldn't stop other forms of test fraud, such as test question collection or calling different time zones with the test questions.

A palm vein scan works like this: A person would hold their hand, palm down, over a computer mouse-sized sensor for a few seconds -- not touching anything. Near-infrared light, the same near-infrared light that changes your television channel, shines out. Most of the light bounces back to the detector and shows up as white on the scan.

Some of the light is absorbed by the veins, and creates dark lines on the otherwise ghostly-looking hand.

The difference between light and dark is basic anatomy. Arteries carry oxygen-rich blood. Veins carry oxygen-poor blood. When red blood cells drop off oxygen they change. Instead of reflecting near-infrared light, the red blood cells in veins absorb it.

It's like a fingerprint inside the body, said Naito, except it's more accurate and harder to fake.

Fujitsu claims their palm scanner is roughly 100 times more accurate than the average fingerprint. Instead of comparing pictures of swirling, curling fingerprints visually, the palm scanner converts the vein scan into digital data that is then run through a computer algorithm that compares the hand hovering above the scanner with the data in memory to authorize access.

If an unauthorized person wanted to gain access it would be difficult. A person's fingerprints can be lifted easily and replicated with some difficulty. It's much harder to gain access to a palm vein profile since people don't leave traces of it on every object they touch with their hands.

The hand also has to be alive, exchanging gasses, and full of blood for the veins to show up on the scan. In grim terms, that means a person couldn't cut off another person's hand and hold it over the scanner.