Judge allows online Oyster cloning guide

Instructions for cloning Oyster cards can be published online, a Dutch judge has ruled.

The information, discovered by researchers at a Dutch university, could allow people to travel free on London's public transport.

The ruling overturns an injunction to suppress it won by cardmaker NXP. Researchers at Radboud University are delaying publication until October, giving users time to adapt their systems.

The flaw is in the Mifare Classic chip at the heart of the Oyster system and the Dutch Rijkspas.

A university spokesman said the result meant "society can be informed about the shortcomings of a product, so that action can be taken against the risks".

A spokesman for NXP said it could take years for users to adapt systems to defend against the attack. However, a Transport for London spokesman said it "remains confident" in Oyster's security and that "any fraudulent card would be identified within 24 hours and be blocked".