Information is all in the cards

They've all got something on you

Cards can already store enough data to identify us by our digitised signatures, fingerprints and even the unique patterns of blood vessels in our retinas. Given that choice, it is cost and convenience - rather than precision - that will determine what sort of cards we must carry around to identify ourselves.

The ID card announced yesterday contains the minimum of technology - a magnetic stripe, holding security details to prevent forgery. But a few countries are already moving towards smart cards - like credit cards, but with a built-in microchip - as national identity cards. South Korea has said that within a couple of years all its citizens will use them as a combined digital voting slip, pension entitlement and medical insurance certificate, driver's licence (with endorsements), health, social security and military service record. In Germany, adults carry smart cards with details of their combined private and public medical insurance - in effect, an identity card by default.

But in Britain, cost is a key factor. "Biometric checks are a very long way off in the UK," says Emma Newham, editor of Biometric Technology Today magazine. "There's enough ruckus over the national card with a magnetic stripe." The cost of a smart card (up to pounds 10, even in volume), and the cost of the reader systems able to communicate with the chip, mean that simpler technologies are likely to prevail. An experiment carried out recently for the Employment Agency in the north of England showed that magnetic stripe cards can store enough data to identify a signature, making it virtually impossible to impersonate someone else.

In a trial in Illinois, claimants for some welfare payments carry smart cards holding their retinal scans. In South Africa, pensioners in the poorer townships use smart cards containing a digitised version of their fingerprint. At the payment office they provide their card and put their finger onto a reader: the two must match before they receive their payment.

In Britain, though, "people are used to signing for benefits, but not to providing their fing- erprints", said Andy Lewcock of AEA Technology, which developed the signature verification software. Similarly, in May the Government awarded a pounds 1bn, eight-year contract to a consortium of companies to automate the Post Office and Benefits Agency's payment systems. The present printed order book that a claimant takes to the payment office will be replaced with a magnetic stripe card, containing the holder's name and National Insurance number. These will be phased in over the next couple of years.