By BBC News Online's Alfred Hermida

A smart card that generates a one-off number every time you use it could help tackle credit card fraud.

Developed by a San Francisco company called PrivaSys, it has an internal chip that can hold your credit and debit card details on a single piece of plastic identical in size and shape to all your other cards.

The smart card comes as the major credit card companies and financial institutions look for ways of making their cards more secure.

Card fraud cost the UK �292.6m in 2000, an increase of 55% in a year, according to the Association for Payment Clearing Services.

Packed with technology

The PrivaSys card has a calculator-styled keypad, a small Liquid Crystal Display (LCD) screen, a thin battery, a special magnetic stripe and a tiny processor microchip.

Ziegler: Card has a small processor

"There were initially big desktop computers, and then we had laptops, then Palm Pilots," explained PrivaSys CEO, Joan Ziegler.

"Now, we've taken that technology and jammed packed it into something the size of a conventional credit card."

The technology patented by PrivaSys enables smart credit cards to generate disposable numbers for each purchase.

When you go to a shop or restaurant, you punch in a four-digit Pin into the card to come up with a unique number to that sale.

The card can then be swiped through existing card-reading devices and the account is debited.

Enhanced security

For additional security, the card has a photograph of the cardholder.

"You have some real-time authentication so if someone stole your card, they couldn't impersonate you because the picture wouldn't match," Ms Ziegler told the BBC's Go Digital programme.

Visa working on its own security enhancements

The LCD display on the card would also let you receive text messages about special offers, perhaps a free soft drink in a fast-food restaurant or an upgrade to first class when seats are available.

"So if you had an airline mileage card, they could send you an offer of double points if you are purchasing a flight on a Tuesday," said Ms Ziegler.

The major credit card companies, Visa and Mastercard, are working on their own schemes to stop fraud.

In a scheme run by Visa, card users attach a password to their card number, making the number useless to a criminal who does not know the password.

For its part, Mastercard's security plan involves consumers' downloading a special software key that would be used by merchants to verify their identity.