Signature tester combats card fraud: Post office customers are guinea pigs in the fight against store crime, Rhys Williams reports

THE LATEST weapon in the fight against credit card fraud - a system for checking signatures on credit card slips - began a four-week trial yesterday.

About 500 volunteers will sign a sheet of paper each time they visit Hedge End sub-post office, near Southampton, so that university researchers can analyse the natural variations in a signature over time and test the accuracy of the system.

An electromagnetic board beneath the paper linked to a computer compares the signatures with those already stored on its database, and, if the system is introduced commercially, the computer could accept or reject a signature at a supermarket check-out within seconds. By analysing the shape of the signature, the timing and rhythm with which it was written, the computer can distinguish variations in speed from letter to letter and monitor movements of the pen in the air.

Dr Eugene Sweeney, an electronics expert at the British Technology Group, which is licensing the system on behalf of the University of Kent, said: 'People need a really objective way of checking signatures. This has got to be better than examination by a human which is much more inconsistent, and prone to other influences such as tiredness and untrained staff.'

As for retailers' fears that genuine card users would be left stranded at the check-out because their signature had changed, Dr Sweeney said: 'You raise the risk of insulting customers, but reduce the risk of forgers.'

Credit card fraud cost banks and building societies pounds 165m in 1992, although the figure for last year is likely to improve to about pounds 130m. Christopher Kay, head of fraud prevention at Barclaycard, said the company had looked at several verification systems over the last three years, including retina scanning and vein prints.

'The two we've ended up with are fingerprint and signature verification. Fingerprinting (whereby a fingerprint is encoded on to the card and read by a terminal at a check-out) seems to have the most promise. Signature verification does work, but we've not been able to get a satisfactory false reject rate - which means falsely rejecting the genuine customer.' Current false reject rates ran at 1 per cent, well short of the company's 1 in 100,000 target. The problem, Mr Kay said, was that the verification technology was originally developed to keep people out of places such as military installations. 'There's a lot of work to be done because we're taking technology developed for one end and trying to turn it round to meet our needs.'

But Mike Isall, who had volunteered to take part in the Hedge End test, said: 'Anything that helps security has got to be good. I can understand that someone in a crowded M & S would be embarrassed if their signature was rejected. But I also think there is not enough done in the way of security, because the losses are enormous.'

John Stranger, the sub-post master at Hedge End, added: 'The country is losing a fortune each year on card fraud and somebody somewhere has to pay for it. People have got to retrain themselves. If they value their card, then they should value their signature and take more time over it. If not, then we're the people who will lose.'

(Photograph omitted)