A part from the robotic voice nagging "please look into the mirror, please look into the mirror" as you line up your eye, it's absolutely painless. There's no flash, not even a click, as the hidden camera takes four digital snapshots of your iris.
Within three minutes your iris pattern - theoretically unique - is stored in a smartcard's memory chip. Short of stealing your eyeballs, no thief can pass themselves off as the legitimate card holder.
Iris-scan biometric security is one of the few James Bond technologies (Moonraker) to become reality. People applying in person for passports recently will have seen an iris-scanning machine at passport offices in London and Glasgow. It's there to test public attitudes to biometrics as part of a consultation into the government's planned "entitlement card".
If, as seems almost certain, the entitlement card gets the go-ahead, it will have at least one biometric security feature to prevent identity theft and other fraud. Iris scanning is the most likely candidate: although nobody claims any technology to be absolutely failsafe, it is more secure and more acceptable than fingerprinting.
But choice of biometric is only one of several big technical questions over the entitlement card, quite apart from the politics of grasping the identity card mettle. Enrolling card holders, issuing new cards and replacements will require a national chain of retail outlets - possibly post offices, possibly private franchisees.
Behind these outlets there will have to be a new database - "a central register of all UK residents". Unlike some continental countries, the UK has no single population database it can use. Most of the government's existing registers are compromised in some way: the national insurance database contains 82m numbers: some people have two numbers, some have never received one. Driving licence numbers are suspect because they change if a person changes their name, and Northern Ireland has a different system to the rest of the UK.
The Passport Agency has a database of citizens, accurate apart from a few thousand "Jackal" passports issued in the names of dead infants. However the entitlement card database would need to include residents who are not citizens. The NHS has the most recent database, renumbered with "unique identifiers" in the 1990s. However, the Home Office consultation rules out the use of the NHS number as it might raise concerns over the confidentiality of medical records. The conclusion is that a new register would have to be created.
According to the consultation document, the government is "examining the feasibility of developing a high-quality common population register, holding core data and a unique identifier on UK residents that could be used across the public sector." This database would hold "a very limited range of core information about people, such as their name, address, date of birth, sex and unique personal number".
Opponents of the entitlement card will question whether the cost of this infrastructure, which will run into billions, will exceed the benefits. According to the Home Office, identity fraud costs the taxpayer £1.3bn a year. But the card has another potential use that may sway the argument, as the key to e-government. According to the consultation document "the card could provide a more efficient basis for administering public services by avoiding the need for people to provide the same personal information time and again to a range of public services".
The theme crops up repeatedly in e-government circles. The e-envoy, Andrew Pinder, says the biggest single problem he faces is authenticating the identity of people contacting government agencies electronically. The first choice, commercial digital signatures, was condemned last week as "costly and time-consuming" by the House of Commons Public Accounts Committee.
The IT industry agrees. "The lack of a personal electronic signature is the single biggest obstacle to e-government," Geoff Llewellyn, head of public sector strategy at SchlumbergerSema, maker of the iris-scanning system, said last week. Llewellyn says he's neutral on the entitlement card, but ready to provide one: "When the political and constitutional debates have been settled, the technology should not be a problem."
