The security of biometrics has been brought into question once again, highlighting concerns about the UK passport scheme. Revelations at Biometrics 2004, including the production of fake irises, have brought into question the likelihood of the scheme rolling out by 2008.

Speaking at the conference Tsutomu Matsumoto, professor of mathematical analysis at Yokohama National University, revealed progress beyond gummi fingers and into the production of fake irises. Explaining how the system could be cheated he pointed to the problems in early iris recognition technology. "In iris matching the presented object is not necessarily a live eye," said Matsumoto.

In response the Home Office have denied the techniques will be an issue. "Enrolment would be an attended operation making the use of artificial biometrics at this stage very unlikely," said a Home Office spokesman.

Some question the feasibility of this. "There's a general feeling that the success of any biometric scheme really depends on the budget," said Marcus Klische, independent biometrics consultant. "A non-monitored, non-controlled environment is dangerous, but manning the stations is expensive."

Also raised was the link between actual identification and biometric information as a potentially weak area. "Internal weaknesses could be a problem. If an administrator is paid enough then biometric identity can be manipulated," Klische said. "Biometrics may make a system more secure. But the more important and forgery proof the card is, the greater the incentive for criminals to use them."

Katherine Courtney, UK identity cards programme director, sees the scale of the challenge ahead. "If the environment is not well thought out data can be unreliable. It isn't going to be possible to avoid the odd false identity being created."

Further fears that biometrics technology has been treading water over the last few years were allayed by the Home Office. "There is work yet to do, but the evidence we have so far give us confidence in the capabilities of biometric technology," said the spokesman.