Hidden Codes in Printers Cracked

r84x writes "A research team led by the Electronic Frontier Foundation (EFF) recently broke the code behind tiny tracking dots that some color laser printers secretly hide in every document. The U.S. Secret Service admitted that the tracking information is part of a deal struck with selected color laser printer manufacturers, ostensibly to identify counterfeiters. However, the nature of the private information encoded in each document was not previously known. "We've found that the dots from at least one line of printers encode the date and time your document was printed, as well as the serial number of the printer," said EFF Staff Technologist Seth David Schoen."

Comments

Maybe its not a weakness

[suso]

Its a good thing that I can't print. [warning: experimental music made from printer noises]

Re:Maybe its not a weakness

[suso]

There is a fine line between Offtopic and Funny.

Printer Friendly Version?

[OctoberSky]

Anyone have a printer friendly version? On second thought.... nevermind. //Tin foil hat on

Re:Printer Friendly Version?

[Smidge204]

Forget the tinfoil hats! Everything I print from now on will be on foil-backed paper!

=Smidge=

Re:Printer Friendly Version?

[LearnToSpell]

Not if they search your house when you're not home! No inconvenience for anyone! In fact, you might not even know they've been there. Everybody wins.

Message decoded

[GroeFaZ]

"If you can read this, you are about to be busted"

Date and time?

[Anonymous Coward]

I bet most people's printers will print "Jan-01 1980 12:00" in little blinking dots.

Re:Before...

[sisina]

Holy crap! 600,000 people are watching every move I make? Where's my Xanax??

Blue light scanner mod ?

[Animaether]

You'd think it would be easier to...

A1. scan as normal
A2. separate the channels into CMYK in Photoshop/whathaveyou
A3. inspect the Yellow channel.

B1. scan as normal
B2. separate the channels into RGB in GIMP/whathaveyou
B3. do a difference matte between the channels
B4. inspect the result

C1. replace the yellow toner cartridge with a black one
C2a. stock the other holders with empty cartridges
C2b. or if that causes a printer error/warning, block the cartridges' output
C3. print

D1. get a sheet of blue filter plastic
D2. scan through that

But I guess the array of blue LEDs with soldering involved is a lot more geeky :)

pacman to the rescue

[Junior J. Junior III]

Just send in the little round yellow guy to eat some of the dots and confuse the feds. No more paranoia!

Re:more links

[meringuoid]

Also interesting is Andrew Bunnie's flat bed page scanner mod to use blue light instead of white. This made the yellow tracking dots easier to see, and the whole page could be seen at once to determine the pattern they made.

Right. So now, in order to ensure that we remain safe from terrorists, paedophiles, and liberals, we need to compel scanner manufacturers to make sure their products will refuse to show the secret codes we already compelled the printer manufacturers to install.

Don't worry, citizen. We have it all under control.

Re:Watermark with extra random patterns

[Mccavity91k]

"What's this? This ransom note was printed in 1455 on printer number 1! Okay men, I think we need to have a little chat with Mr. Gutenberg"