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Eugen @Gargron

TIL: printers do microdots, barely visible yellow dots that encode the timestamp of printing and serial number of the printer. That's how Reality Winner was identified (that's a real name apparently). I'm not sure if all printers have that or only American ones or only NSA ones

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@Gargron @nightpool I'm frustrated that their printer stuff is super old so IDK what the deal is with newer laser printer models :( but at least it seems to be exclusive to laser printers (again, assuming the material hasn't changed in 6 years)

@hoskayne @gargron my understanding is that this affects all modern color laser printers.

@gargron To be clear: the NSA said they identified her through their own internal investigation, just by knowing that it was printed (that's the significance of the much-reported-upon "crease"—once they had proof that the intercept received printed, not electronic ones, it purportedly became much easier to track the leak)

not many people print documents, so it's not unreasonable to think that they could just go through their logs manually.

@gargron but this was a huge opsec failure on the part of The Intercept—they should have known enough to look for them and strip them before publication.

And there's no way of telling what methods the government *actually* used for it's investigation—that's the "parallel construction" at work. They don't have to reveal the existence of microdots in court, because they have the crease as plausible explanation.

@nightpool @Gargron aren't microdots common knowledge already? What would be the point of not mentioning them?

@hoskayne @gargron "common knowledge among tech folk that they exist" vs. "common knowledge among the public that the NSA uses them to conduct investigations" are two different things.

why reveal more sources and methods then you absolutely have to? everything you reveal is just another chance for somebody to hear about it.

@nightpool @gargron

The significance of the crease is the NSA attempting to spread FUD about leaking, and to cast doubt on the intercept.

That's all.

It's to keep us talking about how the intercept screwed up, so other people will be afraid of leaking, and so that we're not talking about the fact that our president is in office because of interference from Russian hackers.

@ajr @gargron nobody actually credible believes the Russians hacked the results of the election, unless I'm misunderstanding you.

The purpose of the crease is to say that leaking is super, super hard. The paper had three forms of identification—that we know about—and the leaker was caught instantly. It had significant space breadcrumbs (where spaces are inserted into words in a way that adds metadata such as the original), microdots, and a (literal) paper trail


All dot-matrix/laser printers, AFAIK. This is long known. Not new.

@Gargron many, many color printers, and it's international. We believe it was originally an anti-currency fraud initiative (I worked on this at EFF)

@Gargron (here's me and Seth Schoen explaining it nearly a decade ago: )

@mala @Gargron I've had a look at various firmwares of Lexmark and only color laser was encrypted

It would be so nice to have fully functional free software firmware for printers.

@Gargron I remember seeing that in a story about domestic Inkjets about 15 years back - I think Canon were the subject, but don't quote me :)

@Gargron This was the interesting technical part that fascinated me when I found out.

@gargron I think professional office type printer / copier devices do this to prevent counterfeiting. E.g. of currency.
@gargron I think it's common among color printers. It's been well known at least in some tech circles for many years now.