Vein Geometry

As with irises and fingerprints, a person's veins are completely unique. Twins don't have identical veins, and a person's veins differ between their left and right sides. Many veins are not visible through the skin, making them extremely difficult to counterfeit or tamper with. Their shape also changes very little as a person ages.

Vein scanners use near-infrared light to reveal the patterns in a person’s veins.

To use a vein recognition system, you simply place your finger, wrist, palm or the back of your hand on or near the scanner. A camera takes a digital picture using near-infrared light. The hemoglobin in your blood absorbs the light, so veins appear black in the picture. As with all the other biometric types, the software creates a reference template based on the shape and location of the vein structure.

Scanners that analyze vein geometry are completely different from vein scanning tests that happen in hospitals. Vein scans for medical purposes usually use radioactive particles. Biometric security scans, however, just use light that is similar to the light that comes from a remote control. NASA has lots more information on taking pictures with infrared light.

Next, we'll look at some of the concerns about biometric methods.

The Future of Biometrics Biometrics can do a lot more than just determine whether someone has access to walk through a particular door. Some hospitals use biometric systems to make sure mothers take home the right newborns. Experts have also advised people to scan their vital documents, like birth certificates and social security cards, and store them in biometrically-secured flash memory in the event of a national emergency. Here are some biometric technologies you might see in the future: New methods that use DNA, nail bed structure, teeth, ear shapes, body odor, skin patterns and blood pulses More accurate home-use systems Opt-in club memberships, frequent buyer programs and rapid checkout systems with biometric security More prevalent biometric systems in place of passports at border crossings and airports