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."

Maybe its not a weakness

[suso]

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

Printer Friendly Version?

[OctoberSky]

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

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:Old Communist ploy gets updated

[$RANDOMLUSER]

I didn't say you were paranoid, you must have imagined that.

CSI: Slashdot

[Anonymous Coward]

Given all the tin foil hat activity lately, I see this as CBS' next spinoff.

I'm all for it. Especially if you get that MILF Marg Helgenberger. Woohooo!!!

Re:Printer Friendly Version?

[Smidge204]

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

=Smidge=

want anonymity

[sucati]

Here's my suggestion: get newspaper or magazine (with big letters preferrably), glue, scissors and some paper. Cut letters of liking, assemble and paste to paper. Oh and wear gloves.

Re:Printer Friendly Version?

[LiquidCoooled]

Print everything with pretty yellow floral background and all will be fine :D

Re:Maybe its not a weakness

[suso]

There is a fine line between Offtopic and Funny.

So remember

[protoshoggoth]

If you're printing out your ransom demands on a color laser printer, send a photocopy of the printout instead.

Re:Maybe its not a weakness

[suso]

What the? Now damnit, why was that marked as funny. Mark my grandparent post as funny.

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"

Yellow toner

[mrjackson2000]

No wonder the yellow always runs out first!

Re:Old Communist ploy gets updated

[mattkime]

And now the US government has made it quick, easy and automated to do the same.

*sigh*

but the US is good and the commies are bad!

God Bless America!

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.

Re:Before... (the Patriot Act)

[Anonymous Coward]

God bless the PATRIOT Act,

Don't forget the 1994 Crime Bill and 1996 Anti-Terrorism Act.

Oh wait. Do forget those. They can't be blamed on Bush, and this is Slashdot.

Re:Printer Friendly Version?

[Basehart]

"All you need is to scan anything that they have printed and copy the hidden code on the page and then use image software to overlay that code onto your own page image and print it using a printer that doesn't embed its own code"

Create multiple layers in photoshop, each with its own secret code. Be sure to title each layer with a name so you don't send Nancy down when it was Joe who looked at you funny that morning last week.

Re:So they "cracked" it...

[Pusene]

This would be fun:

1. Mail local politician and ask for something, get nice letter in reply.
2. Decode info hidden in letter.
3. Create Communist, Satanist and other anti-government propaganda with fake, hidden info.
4.???
5. Profit!

Re:Maybe its not a weakness

[mwood]

Interesting, yes, but too old to be funny. Many moons ago somebody made a program that could play tunes by fiddling with the timing of the hammers on an IBM 1403 line printer. It's good to see someone keeping the traditions alive. :-)