Original URL: http://www.theregister.co.uk/2010/05/05/atm_pin_sharing/

Sharing bank PINs leaves consumers at risk

Although not necessarily, says expert

By John Leyden

Posted in Security, 5th May 2010 10:36 GMT

One in ten consumers either write down or share their ATM card PIN codes, according to a new survey by the UK's Consumer Association.

If a card is fraudulently misused, banks will only provide a refund if the cardholder had taken care of their card and account details. Writing down PIN numbers or sharing them with others violates these conditions and could be considered careless behaviour, the Consumers Association Which? magazine warns.

However, noted banking security expert Ross Anderson takes issue with these conclusions from a 1,000 person poll in a blog posting on the University of Cambridge's Light Blue Touchpaper blog. He argues that it would be wrong for banks to claim individuals are grossly negligent even if they do share PIN numbers. This PIN could be disguised as part of a phone number in an address book with hundreds of other numbers, he points out.

"And if banks don’t want disabled people to share PINs with carers, they ought to come up with an alternative, or be held to account under disability discrimination laws," Anderson adds.

Anderson also notes that banking associations, APACS and now UK Payments Administration, have given contradictory advice about whether or not consumers should use the same PIN codes with multiple cards.

"By giving customers contradictory and impractical advice, the banks are placing an unmeetable burden on them," the Cambridge Don concludes. ®