Contactless bank cards

Tom Thomson colinthomson1 at
Thu Nov 18 00:24:11 GMT 2010

Ian, I think you inhabit a different world from mine.  I use the stores of three three different supermarket chains who operate in my town, all of which open the till on credit card transactions to allow the vendors copy of the cc receipt to be placed in the till.  I've been in supermarkets where this doesn't happen, but far more often in supermarkets where it does, and I don't believe that the supermarkets will pay the extra cost of changing the till system to avoid opening the cash drawer when they change the card reader to operate contactless without pins.

In an ideal world where all the retailers ensure that the cash drawer is not opened for card transactions (except those using cash-back) your argument might be valid; but I don't live in that ideal world, and neither do most people.


> On 16 Nov 2010, at 10:41, Ian Batten wrote:
> Oh, and by the way: ever wondered why shops are so keen on ".99" prices?    Unless
> someone carries a lot of loose change, it means the till has to be opened for every
> transaction.  Unless you operate a shop which prices everything in round pounds
> (round 10 pounds, probably, given that university cashpoints seem to be the last
> place on earth that issue fivers), people who pay cash (who you need for your fraud
> to work) are going to have to be prepared to either not have any change, take their
> change from the pile you keep beside the till or you're going to have to open the till.
> What transaction are you going to ring up to do that, exactly?
> At best, your scheme allows you to replace a transaction from a customer who pays
> the exact price and doesn't want a receipt with a hooky card transaction, until late in
> the evening when there isn't enough cash in the till and you get sacked.   And even
> that's assuming you can spot people who are going to pay the exact amount before
> you ring it up on the till: in practice, people look at the amount and compare it with
> the shrapnel they want to get rid of.    You'll have to find a way to say "that'll be ten
> quid mate" and take the money without opening the till, without anyone else (and
> shops with lone workers tend to have CCTV for H&S reasons) noticing.   You might be
> able to do it if you're a sole proprietor, I guess.
> ian

More information about the ukcrypto mailing list