Identifying you by your veins

A biometric identification technique you may be seeing more of in the coming years is vein scanning. The veins inside a person's hand, or just one of their fingertips, are imaged and the results passed through a software algorithm to obtain a unique identifier for that person. In an identification scenario, that person would then be authorised or denied access, depending on whether their identifier matched one in the database and for which access was granted.

Such devices have been on the market for several years and the technique they use is an optical one called vascular patterning. They typically use an array of near infra-red LED's to illuminate the hand or finger, and a CCD camera on the other side records the resulting image. The infra-red light is absorbed by haemoglobin in the blood and therefore the veins show up distinctly.

Since the scan is of the inside of someone's body, it is far harder to forge the results and fool the system. Damaged areas of skin, which in extreme cases can cause problems for conventional fingerprint scanning, present no problems with this technique because the light passes right through them. Even wearing gloves, which is useful in hospitals or in research facilities where bio-hazards might exist, is acceptable with these machines. In fact, it is not even be necessary to touch the scanner surface at all; holding the hand a few centimetres away is sufficient.

Hitachi and Fujitsu are among the companies that offer commercially available products and there is an ever-expanding market for them, such as ATM's, car doors and controlling restricted areas in secure facilities. They are touted as being fast and reliable, and you can expect to see more of them in everyday use in the near future.