The Biometric Delusion

Following 9/11, the newly established US Department of Homeland Security (DHS) designed US-VISIT, a biometrics-based scheme to protect the US border from infiltration by malevolent aliens. NIST conducted a computer-based trial of flat print fingerprinting to predict the success of US-VISIT. They estimated that the technology would successfully verify identity 99.5 per cent of the time. That is equivalent to a false non-match rate of 0.5 per cent, well within IPS’s one per cent limit.

It may not be immediately obvious how outrageous NIST's forecast is. In the 2004 international fingerprint verification competition, FVC2004, the best algorithm achieved a false non-match rate of 6.21 per cent at a false match rate of approximately zero per cent. Even with a false match rate of one per cent, the best false non-match rate was 2.54 per cent, and IBM promptly formed a partnership with the winning company, Bioscrypt, Inc. No-one in 2004 had ever seen a flat print fingerprint algorithm capable of IPS's one per cent false non-match rate, let alone NIST's 0.5 per cent, and they still haven't.

In December 2004, the US Office of the Inspector General (OIG) reviewed the statistics for the first year of operation of US-VISIT. On average, 118,000 people a day presented themselves to primary inspection at the borders. Primary inspection is largely a biometrics check. If the false non-match rate is 0.5 per cent, you would expect 590 of them to fail and to be referred to secondary inspection by human beings. The actual figure was 22,350 failures or 19 per cent. Just like in the UKPS biometrics enrolment trial.