color printers have secret tracking code

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Sleuths Crack Tracking Code Discovered in Color Printers

It sounds like a conspiracy theory, but it isn't. The pages coming out of
your color printer may contain hidden information that could be used to
track you down if you ever cross the U.S. government.

Last year, an article in PC World magazine pointed out that printouts from
many color laser printers contained yellow dots scattered across the
page, viewable only with a special kind of flashlight. The article quoted a
senior researcher at Xerox Corp. as saying the dots contain information
useful to law-enforcement authorities, a secret digital "license tag" for
tracking down criminals.

The content of the coded information was supposed to be a secret,
available only to agencies looking for counterfeiters who use color
printers.Now, the secret is out.

Yesterday, the Electronic Frontier Foundation, a San Francisco consumer
privacy group, said it had cracked the code used in a widely used line of
Xerox printers, an invisible bar code of sorts that contains the serial
number of the printer as well as the date and time a document was
printed.

With the Xerox printers, the information appears as a pattern of yellow
dots, each only a millimeter wide and visible only with a magnifying glass
and a blue light.

The EFF said it has identified similar coding on pages printed from nearly
every major printer manufacturer, including Hewlett-Packard Co., though
its team has so far cracked the codes for only one type of Xerox printer.

The U.S. Secret Service acknowledged yesterday that the markings, which
are not visible to the human eye, are there, but it played down the use for
invading privacy.

"It's strictly a countermeasure to prevent illegal activity specific to
counterfeiting," agency spokesman Eric Zahren said. "It's to protect our
currency and to protect people's hard-earned money."

It's unclear whether the yellow-dot codes have ever been used to make an
arrest. And no one would say how long the codes have been in use. But
Seth Schoen, the EFF technologist who led the organization's research,
said he had seen the coding on documents produced by printers that
were at least 10 years old.

"It seems like someone in the government has managed to have a lot of
influence in printing technology," he said.

Xerox spokesman Bill McKee confirmed the existence of the hidden
codes, but he said the company was simply assisting an agency that
asked for help. McKee said the program was part of a cooperation with
government agencies, competing manufacturers and a "consortium of
banks," but would not provide further details. HP said in a statement that
it is involved in anti-counterfeiting measures and supports the
cooperation between the printer industry and those who are working to
reduce counterfeiting.

Schoen said that the existence of the encoded information could be a
threat to people who live in repressive governments or those who have a
legitimate need for privacy. It reminds him, he said, of a program the
Soviet Union once had in place to record sample typewriter printouts in
hopes of tracking the origins of underground, self-published literature.

"It's disturbing that something on this scale, with so many privacy
implications, happened with such a tiny amount of publicity," Schoen
said.

And it's not as if the information is encrypted in a highly secure fashion,
Schoen said. The EFF spent months collecting samples from printers
around the world and then handed them off to an intern, who came back
with the results in about a week.

"We were able to break this code very rapidly," Schoen said.


from the Washington Post