
EFF's “Yellow Dots of Mystery” (2008) - chdir
https://www.eff.org/deeplinks/2008/10/effs-yellow-dots-mystery-instructables
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schoen
Hi folks, I wrote a lot of this and appear in the video.

I thought at the time that the most significant part of this is that private
companies would agree to participate in secret government programs to modify
the design of their technology, even without being legally compelled to, and
then most of them would not talk about it. That's a bigger deal than what the
particular technology actually does.

I still think that was exactly right.

The second-biggest part for me is that a lot of people don't see a core value
in anonymous publishing, so we see some technologies with intentional forensic
marking of documents -- especially this and optical media, which the recording
industry and U.S. government have pushed to have marked with indications of
where discs were manufactured. Those technologies are a major threat to
underground and samizdat media because a government has an unambiguous
starting point to figure out what device or facility produced the documents.
Document forensics exists, and it will always be possible to learn something
about the provenance of a document by physical examination, but actually
putting device serial numbers into the documents -- especially without clearly
warning the users -- is way uncool if you think there should be able to be
anonymous mass media.

~~~
tedunangst
Without weighing in on the merits, it's not uncommon for companies to
preemptively adopt self-regulation in an effort to keep legally compelled
regulation at bay.

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deeviant
NSA advocate: But it's OK, only the NSA can decode the data and they only use
the data for legitimate nation security.

Some nerd: The code has been cracked and anybody can download a program to
decode them, giving access to private and possible sensitive data to anybody
who wants it.

NSA Advocate: Hmm, next time will make the code harder to crack or something
other than stopping to coercing businesses from building in far-from-
impenetrable back doors into public consumer products that are used by
hundreds of millions.

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throwawayaway
some related and useful info:

[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)

i wonder if mono black laserjets have similar issues.

~~~
joosters
From the linked 'seeing yellow' site:

"They are present in both color printers and copiers but do not show up in
pages printed in black-and-white mode."

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msandford
Because you can't print counterfeit currency with black and white, which is
ostensibly the reason the whole thing got started.

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arobertson
Couldn't you replace the black ink with green ink and then print in "Black and
White" mode?

~~~
msandford
My guess is that you wouldn't get the shades right. Maybe with a lot of trial-
and-error, but at some point it's easier to just make some printing plates and
go that route. Either way the paper is the real problem.

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nmridul
Time to start a Paper company with pre-printed random yellow dots in it... The
pre-printed dots should confuse the hell out of the Printer-printed dots....

~~~
mroemore
In terms of anonymity though, there'd have to be a lot of people buying your
paper to avoid uniqueness any individual document. Maybe you could buy,
rebrand and resell the most commonly sold yellow paper as 'Super Secret
Document Paper'!

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reustle
I wonder if it is this sort of thing, along with patents in the industry, that
prevents open source printers from taking off.

~~~
dfox
There is nothing that prevents one from making opensource laser printer.
Except the fact that the whole mechanism is decidedly non-trivial to get
right. You get precision mechanics, high voltage, large resistive heating
element and multimegabit serial datastreams that have to be phase locked to
mechanical movement in one little box that can be bought off the shelf for
<100USD. For that matter many "printer manufacturers" actually buy the whole
print engine as a module from somebody else as there is not much to be gained
by designing and manufacturing it in-house.

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unics
When Color laserjet copiers first started being manufactured to the present
quality that they are now I understand that the Treasury Dept requested
manufacturers to include serial numbers in printed copy to track forgers of
currencies. Microscopic serial numbers can be found within images interspersed
throughout the image.

~~~
cyphunk
The 21C3 lecture from Stephen Murdochs on reverse engineering photoshop and
printers attempting to detect currency also of interest.

[http://www.cl.cam.ac.uk/~sjm217/projects/currency/](http://www.cl.cam.ac.uk/~sjm217/projects/currency/)

[http://events.ccc.de/congress/2004/fahrplan/event/108.en.htm...](http://events.ccc.de/congress/2004/fahrplan/event/108.en.html)

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kghose
Use FedEx Kinko's. Wear a baseball cap and sunglasses when you go in.

~~~
throwawayaway
with your phone left behind you and having dodged any security cameras between
there and where you live.

...and all you want to do is print some flyers for a bake sale.

~~~
tedunangst
If the secret police want to know where your bake sale is, they'll probably
just read the address on the flyer instead of decoding the magic tracking
dots.

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johnchristopher
I wonder if something like that is implemented in 3D printers.

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joosters
... to stop someone forging gold bars?

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Zigurd
Presumably such a mechanism in 3D printers would be used to try to stop people
from printing guns and anything else a government might frown upon, like drug
paraphernalia, etc.

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madaxe_again
Related:
[http://en.wikipedia.org/wiki/EURion_constellation](http://en.wikipedia.org/wiki/EURion_constellation)

~~~
ZeK__
NOT related. This is not meant to track you. This is just a marking.

~~~
jellicle
It's a subliminal marking that is also a software instruction honored by most,
if not all color copiers and scanners and many graphics software applications.

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plg
so can someone post a link to a tool or tools where one can decode these dots?

