The U.S. Transportation Security Administration (TSA) recently completed testing of biometric products for use in access control at U.S. airports. The Qualified Products List (QPL) for Biometrics for Airport Access Control lists the devices that have passed the rigorous testing protocol set out by the TSA. The four products that made the grade are readers from Bioscrypt, Cogent and two from Lumidigm. All four are based on fingerprint biometrics.
The QPL was created to provide guidance to U.S. airports in the selection of biometrics for use in their facilities. After the Sept. 11 attacks, many airports wanted to augment card access systems with biometrics. The advantage of the upgrade was obvious: a card-based access system (what you have) verifies the card, but not the person holding it. Only biometrics (who you are) can positively verify the actual cardholder. The creation of the QPL puts airports’ concerns about meeting specific TSA standards to rest.

San Francisco International Airport (SFO) was the first to use biometrics at all doors leading to the tarmac — and more than 200 access points have been biometrically secured at SFO since 1994. Other large international airports such as Seattle and Boston have also adopted biometrics, along with some smaller airports, such as Toledo International.

The QPL testing ensures that all of the devices that make it on the list have passed a minimum level of capability. Testing was conducted with the help of the International Biometric Group (IBG) and included the use of more than 250 subjects that were representative of a typical airport population in gender, age and occupation. The subjects visited multiple times over a period of six weeks to best simulate a real use pattern for an indoor application.
In addition to performance capability, the listed products had to meet a required set of specifications, ranging from electrical and environmental needs to biometric interoperability standards, such as ANSI 378 — a recognized fingerprint standard.

Seven different products were tested; and four (all fingerprint products) made the list. Bioscrypt and Cogent’s offerings both use conventional fingerprint sensing technologies — optical and silicon, respectively. The two Lumidigm offerings make use of a new type of fingerprint technology: multispectral imaging. Multiple wavelengths of light are used to capture an image of both a person’s external fingerprint and their identical “internal fingerprint.”

The internal fingerprint lies about 2 millimeters (1/8-inch) under the surface of the skin. It is made up of tiny blood vessels called capillaries. During skin development, collagen squeezes between these capillaries and makes its way to the surface of the finger to form the ridges of the external fingerprint. Thus, the patterns of the internal print and external print are identical, ensuring a clear image of a person’s fingerprint, regardless of the condition of the person’s finger and the environment the system is in.

The TSA’s guidance document which defines the testing parameters for the QPL recognizes the importance of outdoor applications. Many airports have the need to biometrically protect perimeter gates and other exposed access points. However in this first round of QPL qualification, only the indoor portion for the testing was run. Airports may want to take this into consideration for their evaluations.

Bill Spence is vice president of transaction systems at Lumidigm Inc. He leads the Lumidigm business unit that applies patented multispectral fingerprint technology to transactional systems in markets such as physical access control and time-and-attendance.