By Jacqueline Ali
BBC News Online
Plans to introduce identity cards in Britain may be premature because the technology may not be up to the task, a panel of experts has concluded.
The government is working towards a national introduction of cards
Overall, the scheme is likely to be a positive step for society, and should go ahead, the researchers argue.
But they think the technology could potentially be abused and would be ineffective in some cases.
The UK government is conducting small-scale trials, and hopes to begin phasing in ID cards in the next decade.
They would involve physical information being taken from each of the 60 million people living in Britain.
This "biometric" information would take the form of an iris scan, fingerprint or facial scan.
It would then be stored on a microchip embedded within the card.
When presenting the card, the information would be checked against a national repository, or database.
The experts spoke to journalists at the Royal Institution in London.
Neil Fisher, director of security solutions at technology group QinetiQ, told the reporters the rationale of the Home Office for implementing the scheme - to deter illegal working and tackle immigration abuse, and strengthen the country's security - was in his view all wrong.
Rather, it was a "golden opportunity" for Britain to set a new standard in our digital era, he said.
But added the scheme would need to be "low cost and future proof".
Mr Fisher acknowledged public fears about how their personal information was used would have to be allayed.
Some lobby groups have complained that the scheme would be an infringement of civil liberties.
Biometrics is by no means infallible. As with any technology, the complicated processes behind it are always liable to breakdown and error. Nor will they be immune to attack.
"It gives the impression that it is ready for large-scale deployment," said Dr Farzin Deravi, an expert in information engineering at the University of Kent.
"The truth is further away. Large-scale implementation will present many problems and challenges. The ability of a biometrics system to work at this scale is unproven."
Dr Deravi said that ID cards had recently been catapulted into the spotlight due to terror incidents, but he argued there was no proof that the cards could combat terrorism.
Other complications include the fact that not everyone will be able to enrol in the scheme.
In some rare cases, people with eye problems, or with damage to their fingertips, will not be able to give accurate information.
This difficulty may even extend to individuals who carry out heavy labour, if the skin on their hands is very thick or worn away.
Biometrics may also be less effective in younger citizens, and people from certain ethnic backgrounds.
One such solution would be using "multimodal" biometrics - where more than one physical characteristic, such as eyes and fingertips, is checked.
But the system could also potentially be abused by way of false fingertips, photographs of irises or even masks, according to Dr Deravi.
"There are ways around it, but they are not simple," he said.
Professor John McDermid, from the University of York's computing department, said there were positive aspects to the scheme.
"There are many instances where I would find an ID card useful," said the professor.
He argued that vital questions still needed to be addressed - such as whether the government could deliver within a reasonable timescale, what the detailed technological requirements were, and whether the system could really meet the government's objectives.
At present, answers to these questions were decidedly hazy, he believed.
"The government doesn't seem to have worked out its requirements yet.
"There are many big and fundamental questions they don't appear to have an answer to."