It is "frighteningly easy" for criminals to get security details for a Visa debit or credit cards, according to research from Newcastle University.
Fraudsters are able to work out expiry dates and security code numbers by making multiple invalid attempts on different websites, the team claims. It is thought a similar method was used in the recent Tesco Bank fraud hack. Visa said the research did not take into account other layers of security such as its Verified by Visa system. According to the research, which has been published in the journal IEEE Security & Privacy, fraudsters use a so-called Distributed Guessing Attack to get around security features put in place to stop online fraud.
'Unlimited guesses'

Mohammed Ali, a PhD student at the university's school of computing science and lead author, said: "The current online payment system does not detect multiple invalid payment requests from different websites. "This allows unlimited guesses on each card data field, using up to the allowed number of attempts - typically 10 or 20 guesses - on each website. "Also, different websites ask for different variations in the card data fields to validate an online purchase. This means it's quite easy to build up the information and piece it together like a jigsaw.....Read more here