IF WE can believe the politicians, biometric technology offers the world’s first foolproof identification system. The use of iris patterns or fingerprints on ID cards, says the Home Secretary, “will make identity theft and multiple identity impossible — not nearly impossible, impossible”. This certainty is echoed by the Home Office minister Fiona Mactaggart, a former chairwoman of Liberty who once denounced ID cards as an outrage. Now, she says, the “security and opportunity” of biometrics has convinced her that this “revolutionary” hi-tech solution is the only way to protect personal identity.

Get nervous whenever you hear ministers extolling the benefits of a magical new technology. Whitehall has an impeccable record of making IT promises that it failed miserably to deliver. With most over-hyped government IT projects, it normally takes a few hundred million extra pounds and a couple of years’ delay to put things right. If a vast national biometric database goes wrong, the costs could be far greater.

Iris recognition, for instance, may one day be as effective as DNA at proving an individual’s identity, but we have no idea how it will work on a national scale. Last March the US General Accounting Office reported that the largest iris-recognition system yet developed contained as few as 30,000 records. How effectively such a system would perform on a national scale, the GAO concluded, remained “unknown”.

As for David Blunkett’s conviction that a biometric record will guarantee an individual’s identity without any “false positive” readings, the evidence is lacking. Last year, after rigorously testing leading iris-scanning and face-matching products, the US Defence Department reported that they were far less effective than their manufacturers claimed.

Eye-scanning software from Iridian, for instance, claims a 99.5 accuracy rate; the Pentagon found that it worked only 94 per cent of the time. As for Visionics’ “face-recognition” technology, which maps patterns on individuals’ faces, it recognised people in tests barely 51 per cent of the time, rather than the 99.3 per cent claimed.

There have been too many abandoned trials of biometric recognition to make Mr Blunkett’s certainty appear realistic. Even if he does find a technology that works perfectly at a national level, a couple of problems will remain. As Britain will have to accept biometric ID cards from elsewhere in Europe, what is to stop an identity thief or criminal faking the details of someone from across the Continent? And what happens when a fraudster tricks an iris-scanning machine by using a digital image of somebody else’s eye?

Over to you, Mr Blunkett.

IT HAS NOT yet found any space aliens, but “distributed computing” is causing a stir in the medical world. This is the harnessing of ordinary PCs’ spare processing power over the internet — most famously by SETI@home, which has more than 500,000 computers searching for extraterrestrial intelligence. Now a project based in Evesham, Worcestershire, says it has used 13,000 volunteers’ computers to identify 42 molecules with potential cancer-fighting properties. The Find-A-Drug scheme says its community has given the equivalent of 1,000 years’ computing time. It is a healthy start, although some way behind an Oxford University project using 2.5 million computers to provide 225,000 years of medical number-crunching. Before logging off tonight, you may want to search Google for some medical distributed computing software to download. You might just save some lives.

DAVID ROWAN