Sir, The National Physical Laboratory (NPL) is the UK’s national measurement institute, and was commissioned to undertake a study into the use of biometrics (letter, May 23) as a unique identifier of a person in a national identity database. This study has been much quoted and misquoted since its publication in February 2003.

The identity cards programme proposes two uses for biometrics. The first use is to uniquely identify a person when they enrol for an ID card (to detect any previous registration). This was the focus of the NPL study. The second use is to allow people to verify a link to their previously established identity.

Initial identification and enrolment of a person requires the biometric to be very accurate, hence our recommendation towards using all ten fingerprints or both irises for this task, possibly in combination with facial recognition. We did not state that fingerprinting was more accurate than iris recognition, but concluded that either of these biometrics, properly implemented, could meet accuracy requirements.

For verification, the accuracy requirements are not so severe but usability and speed of use are more important than at enrolment. Using one or two fingerprints or an iris scan, together with an ID card, may well be appropriate.

This is similar to the scenario that many people will be familiar with for online or telephone banking, where several passwords or numbers are required in the joining process, but to verify you as the account holder only a subset of these is used.

Yours,
TONY MANSFIELD
(Head of Biometrics),
National Physical Laboratory,
Hampton Road,
Teddington, Middlesex TW11 0LW.
enquiry@npl.co.uk
May 24.

From Mr Guy Herbert

Sir, The Home Office’s approach to selling its identity scheme as value for money against fraud (report, May 26) is fascinating.

Would you buy a car from a man who was prepared to make assurances about fuel consumption, but not describe the marque, model, engine, performance or safety features (other than that they would be better than anything else in the world), who also refused to tell you how much it cost on grounds of “commercial confidentiality”, and where he reserved the right to decide later to swap it for another model?

Yours truly,
GUY HERBERT
(General Secretary),
NO2ID,
Box 412, 78 Marylebone High Street,
London W1U 5AP.
general.secretary@no2id.net
May 26.

From Mr Peter D. G. Raven

Sir, I am a British citizen living in Singapore. I have a plastic card issued by the Singapore Immigration Authority complete with a photograph and computer chip. It allows me to leave and re-enter the country freely without having to show my passport. Identification is by fingerprint recognition matched with data on the computer chip.

This is considered totally secure by the authorities here — and it costs less than £10.

Yours,
PETER D. G. RAVEN,
8 Butterworth Lane,
Singapore 439423.
peter@peterraven.com
May 26.

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