[Infowarrior] - Confused Xerox copiers rewrite documents, expert finds

[Richard Forno]

6 August 2013 Last updated at 08:28 ET

Confused Xerox copiers rewrite documents, expert finds

http://www.bbc.co.uk/news/technology-23588202?print=true

Photocopiers made by Xerox are changing numbers on documents, a German computer scientist has discovered.

David Kriesel found that copies he made of construction plans had altered room dimensions.

Other users have replicated the problem, which has been blamed on faults with compression software used by several Xerox models.

The company has not yet issued a fix for the problem, but it told the BBC it was preparing a statement.

Mr Kriesel said he worried that numbers could be altered on invoices and other important documents.

Shrinking room

He questioned whether incorrect figures could leave a company liable to legal action.

Niri Shan, a partner at London-based law firm Taylor Wessing, told the BBC it could raise interesting legal implications.

"The person who provided the figures would be liable [for any issues]. Then the question would be, could they turn round to the photocopying company and say, 'Hold on a minute, this is your fault'?

"Often in commercial contracts, the manufacturer may have limitations of liability on consequential loss."

In his tests, Mr Kriesel found that often the number "6" would be turned into an "8", and vice versa, with other numbers being affected too.

One room on his copied plans had its dimensions shrunk from 21.11m to 14.13m.

Substitute figures
He said the anomaly is caused by Jbig2, an image compression standard.

Image compression is typically used in scanners and copiers to make file sizes of scans smaller.

Jbig2 would substitute figures it thought were the same, meaning similar numbers were being wrongly swapped.

Mr Kriesel said the two models affected were the Xerox Workcentre 7535 and 7556.

However, since posting details of the fault online, several other users have come forward with problems on other machines.

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