nationwide card readers

2ndjools

How - ie by what means - do these cards actually work? How does the computer - or nationwide - know that the 'random' number which comes up on the cardreader 'connects' to the payment details online?

Can't fathom it out - ie, obviously no connection(?) between card-reader and pc...? Or is there?

RichPyke

No, there is no connection between the card and PC.

It's all complex mathematical alogrithms and other stuff that I can't spell.

benjus

No, there's no connection.

I have a device I use to connect to computers at my office. It's just a little key fob with an LCD screen displaying a number which changes every few seconds. The computers at my office are generating the same sequence of numbers, so typing in the correct number shows that I have the key fob (I also have to enter my password etc).

The Nationwide card reader works in a similar way. You insert the card and type in a reference number and an amount. The card reader performs a calculation which uses the information you typed in combined with some information from the card to generate the "random" number. The computers at Nationwide have the same information available to them, so they can perform the same calculation and verify that you have given the correct answer. There is probably also some time-dependent element (similar to the device I use to connect to my office) built into the card reader.

2ndjools

Many thanks - complicated, but makes sense - at last. A great help to my sanity... to have it explained. Much appreciated. Great forum, this - like rest of this site. 2ndjools