
Most laser printer printed pages have tracking watermark - ww520
http://brahmsyellowdots.blogspot.com/2008_10_01_archive.html
======
Natsu
Well-known, I'm afraid. You can find more information here:

<http://www.eff.org/issues/printers>

<http://en.wikipedia.org/wiki/Printer_steganography>

It's probably related to the counter-measures against printing currency:

[https://freedom-to-tinker.com/blog/felten/photoshop-and-
curr...](https://freedom-to-tinker.com/blog/felten/photoshop-and-currency)

There's some interesting information about what causes an image to be detected
as currency here:

<https://www.cl.cam.ac.uk/~sjm217/projects/currency/>

~~~
tripzilch
Well-known indeed (at least, I followed it with keen interest when it came
out), but I think it's good that this resurfaces as I really don't think it
got enough attention the first time around.

Personally I think the most worrying bits of data are first the time stamp,
and second the printer serial number.

I say serial number is second because in a criminal investigation phorensics
can also get a "fingerprint" of the printer by tracking imperfections in the
way it's printed.

But the timestamp of when something was printed is definitely new information
that otherwise would not be there and in certain circumstances would not want
to be leaked.

~~~
burgerbrain
_"I say serial number is second because in a criminal investigation phorensics
can also get a "fingerprint" of the printer by tracking imperfections in the
way it's printed."_

I know they used to be able to do that with typewriters, but can they do it
with printers as well? I would suspect the imperfections of being too chaotic,
or at least easy enough to change by changing the cartridge.

~~~
SageRaven
I think it was a Purdue group that documented fingerprinting techniques on
scanners and printers. Seems that stepper motors have fairly unique
characteristics among models and even individual devices (though, with less
accuracy).

~~~
electromagnetic
Anything helps. Even if you can say it was printed on a Cannon over a HP can
potentially narrow things down.

I personally don't see what the huge deal is. I mean we're not going to get
hauled off for disseminating communist literature and I don't think anyone
plans on printing currency.

So I don't know where the huge privacy concern whatever comes from, because
unless you regularly forge time stamps on documents then I really don't know
what the issue is.

~~~
barrkel
* Government whistleblowers

* Large corporation whistleblowers (may have resources to hire PIs with connections to track)

* Civil dissent: think Arab Spring, not communist literature. The technology is not restricted to populations living under liberal regimes.

------
srik
Here's a list of printers that do/dont do that, compiled by EFF.
[https://www.eff.org/pages/list-printers-which-do-or-do-
not-d...](https://www.eff.org/pages/list-printers-which-do-or-do-not-display-
tracking-dots)

------
kevinpet
Reminds me of the typewriter registration in East Germany.

~~~
droithomme
Yep, good observation, it really is the same thing, and amazing people put up
with it.

~~~
nekojima
In East Germany you didn't have a chance (unless you wanted to be in prison or
even more surveillance) and nowadays, most people don't know this is occurring
and so its not an issue.

There might even be a bias against publicizing it by media, as the encoding
has assisted police in several cases to track down criminals or alleged
criminals.

------
dsr_
Ahem. Most COLOR laser printers have tracking "watermarks". It's because the
US Treasury frowns on printing your own replica currency, which would be
unastonishingly easy to do with a color scanner and printer.

~~~
kijin
Isn't that why actual money has all those fancy strips and bumps? Canada just
introduced $100 polymer notes this week. It's even partially transparent. Good
luck faking that with consumer-grade laser printers. (Color inkjets might work
better on transparent sheets.)

~~~
sliverstorm
Why on earth would anyone bother forging Canadian currency?

Just ribbing on ya :p

It is true, there are other preventative measures, but any one measure can be
beaten. It's like computer security- any computer can be hacked, it's just a
game of making it hard enough to hack that it is not worth it, or takes too
long.

~~~
kijin
Sure, any anti-counterfeit measure can be beaten, but it is certainly possible
to design banknotes in such a way that consumer-grade printers can't produce
anything remotely resembling a real banknote. Then there will be no excuse for
spying on citizens' everyday printing activities.

The fact that this alternative is not even on the table adds to the impression
that the U.S. government, as usual, is trying to use Big Bro techniques as a
quick fix instead of coming up with real solutions.

BTW, I'm not sure if anyone prints fake Canadian money, but a few years ago
some dude in Germany tried to print millions of dollars worth of fake Canadian
Tire money :)

~~~
sliverstorm
I really doubt the government is regularly spying on your printing. The whole
thing really seems like a very small issue to me. It just gives printers a
"fingerprint" that can be referenced if needed.

I suppose if "fingerprints" are so bad, we should probably outlaw ballistic
analysis linking a bullet to the gun that fired it?

~~~
DanBC
> _I really doubt the government is regularly spying on your printing._

For some values of "the government" not including many governments; see
$OPPRESSIVE_REGIME.

There's a lot of stuff "the government" does now that would have been
unthinkable before various terrorist bombing attempts. Really, forcing
everyone to remove their shoes before boarding a plane?

And, if you doubt that the US[1] spies on its own citizens you should have a
look at the Echelon programme, where a legal loophole was used by the US to
gather intelligence on its citizens. (The US gov can't do it legally, so they
pass a name onto another gov involved in Echelon.)

[1] US, UK, Australia, New Zealand and Canada.

------
droithomme
Yeah, I only buy lasers that don't have them, there are lists out there of
which ones.

The yellow doesn't photocopy well so if you have to use such a printer, you
can erase the tracking dots on your anonymously distributed pamphlets by
monochrome photocopying at Kinkos the master copy you produced with your home
or business laser.

~~~
daralthus
Make sure you destroy the copier too. :)
<http://digitaljournal.com/article/291894>

~~~
a3camero
At the UPS location near me they make a point of informing you that the memory
is cleared automatically. They seem to be aware of this.

~~~
giardini
A local Fedex Office was completely unaware of this as of 5 weeks ago.

------
Tichy
That is really, really old news :-)

~~~
Nrsolis
REALLY old news.

The EFF has something on this and cracked the code a long time ago:

<http://w2.eff.org/Privacy/printers/>

<http://w2.eff.org/Privacy/printers/docucolor/>

------
grandalf
Wouldn't it be easier to just add additional faint yellow dots to make the
intended pattern impossible to determine?

~~~
blahedo
This is a great idea. Once you know the grid pattern, you could probably just
overlay your documents with faint yellow dots on that grid; if noticeable at
all it would come across as a very faint yellow haze, but that's a tradeoff.

------
ck2
The real crime here is there is no documented law these companies are
following.

They are obviously doing it under legal pressure - so where is the law on the
books?

This means it's a secret law that (at least the) American public is unable to
inspect and attempt to abolish.

Perhaps it's a secret part of the DMCA? What other laws do we not know about?

~~~
tomkarlo
Why do you assume there has to be a law or legal pressure?

Lots of industries adopt practices like this to _avoid_ a situation where
something will become a matter of law, because it has little or no impact on
the sales of their products. If you're a color laser printer manufacturer,
agreeing to do this is probably a lot better than maybe having the government
regulate sales of your product or otherwise add red tape.

------
ajays
On a similar (but tangential) note: US currency notes have similar yellow
circles, which are detected by photocopiers, which, in turn, then either (a)
refuse to photocopy them, or (b) mangle the copy (put vertical bars through
it).

Try photocopying a $20 bill on a copier and see for yourself.

~~~
kijin
Careful there. The copier might automatically notify the Secret Service, too.
You never know with today's network-enabled copiers...

~~~
jrockway
I doubt that the Secret Service will get there quickly enough to arrest you. I
also doubt that they would have enough evidence to arrest you for anything.
Putting a $20 bill in a copy machine is not a crime.

------
blahedo
A good story, but you should really start reading it from the beginning:

<http://brahmsyellowdots.blogspot.com/2008/10/it-begins.html>

------
peterknego
One could mess up "the system" by printing several times on the same sheet of
paper (possibly also changing orientation top-down).

------
code_duck
I'm far more interested in what may exist along these lines for digital
cameras.

------
giardini
Another surprising fact: most digital copiers have a hard drive and they
usually aren't wiped when removed from service.

So everything you copied at the office or at FedEx Office is available even
after you leave:

[http://www.cbsnews.com/stories/2010/04/19/eveningnews/main64...](http://www.cbsnews.com/stories/2010/04/19/eveningnews/main6412439.shtml)

------
Aloha
Or just use a Black and White Laser Printer?

Really, anything you print, no matter what it is printed on with enough time
an effort could be track back to at least the model and type of printer.

------
lallysingh
So, how does this work with duplication equipment? Can I print an original and
color-copy it?

Edit: Or just add yellow dots to the document I'm printing?

------
uiri
Do inkjet printed pages produce similar watermarks? Or is it just laser ones?

~~~
mhyee
From the EFF pages linked to in this discussion and Brahm's first post, it
seems only colour laser printers have the watermark. (Also
<http://seeingyellow.com/>). So black and white laser and inkjet should
hopefully be fine.

