The GIMP threatens PIN number security

Linux image manipulation black ops

This must be a first: Linux image manipulation programme the GIMP has been fingered as a possible tool in uncovering people's PIN numbers as sent through the post. It's not all open source gloom, though, Photoshop can also be used to, in certain circumstances, enhance illicitly-obtained printed PIN numbers.

That, at least, is the conclusion of University of Cambridge reserachers who looked at the tamper-proof stationery used to deliver said numbers to expectant punters. Team member Mike Bond first became suspicious when he was "sent a new pin and found that poor printing meant it was readable with the naked eye", the BBC reports.

This was despite techniques such as secure envelopes which make it obvious if someone has opened them, and peel-off labels designed to obscure printed numbers.

Mr Bond explained that, for example: "You are printing black toner on to a background pattern that is supposed to disguise it," but that: "If you add too little you cannot read it but too much will make it stand out."

The Cambridge staionery-busters were able, using a variety of techniques including the good-old "shining bright lights at an angle to the paper" and the simple scan-and-adjust ploy noted above, to defeat many of the banks' best-laid security plans.

Mr Bond admitted: "We were surprised that it could be done so easily. We're concerned as academics and outside parties that other people are going to be spotting this too and start working towards fraud."

The banks, though, are not overly concerned. A spokeswoman for Apacs told the BBC that little fraud had resulted from the reading of PIN numbers from secure stationery, noting: "A pin has no value without the card." ®