Biometrics – IPS, the Flat Earth Society and transformational cosmology

Tony Mansfield and Marek Rejman-Greene’s report makes the distinction between two different jobs for biometrics – identification (section 2.1) and verification (section 2.2).

Identification is the job of proving that each person has one and only one entry on the population register. Professor John Daugman, the father of biometrics based on the iris, demonstrates easily that that job is not feasible for large populations.

Suppose that there were 60 million UK ID cardholders. To prove that each person is represented by a unique electronic identity on the population register, each biometric would have to be compared with all the rest. That would involve making 1.8 x 10¹⁵ comparisons.

Suppose further that the false match rate for biometrics based on either facial geometry or fingerprints was one in a million (1 x 10^-6). It isn’t. It’s worse than that. But suppose that it was that good, then there would be 1.8 x 10⁹ false matches for IPS to check.

It is not feasible for IPS to check 1.8 billion false matches. It is therefore not feasible for these biometrics to do their identification job.

Verification on the other hand, according to Tony Mansfield, is millions of times easier, and requires only that your facial geometry match the photograph recorded on your ID voucher (whether a passport or an ID card or a biometric visa) or that your fingerprints match the templates recorded on the voucher that you proffer to an immigration control officer, for example, or to a bank manager or to a GP, to underpin your transactions and interactions with them.

It may be millions of times easier, but can the biometrics chosen for the NIS achieve even the job of verification [2]?

Apparently not.

In 2004, the UK Passport Service (UKPS, now IPS) conducted a biometrics enrolment trial. 10,000 of us took part and a report of the trial was published in May 2005.

Under the heading Key Findings (para.1.2), sub-heading Verification success rates (para.1.2.1.4), the report says that 31% of people could not have their identity verified using facial recognition technology – they were told that they did not match the photograph of them taken only five minutes before.

That was just the able-bodied participants. For the disabled, the false non-match rate was 52% – everyone would do better to toss an unbiased coin.

And, using flat print fingerprinting technology [3], 19% of the able-bodied participants could not have their identity verified, and neither could 20% of the disabled [4].