@vkc Related: a lot of things labelled as "fax machine" can actually also function as stand-alone USB printers. And "fax machines" are often free on classifieds, and use cheap generic cartridges/toners, and (aside from stuff like doorbell cameras) that means there's basically no paper or money trail from the original purchaser to you at all.

It's not a bad way to get hold of a more or less anonymous printer.

@Aprazeth @ozzelot @vkc good old 120 columns Brother printers... They'd shake the table like a washing machine

@vkc The dot decoding was used in episode of The Night Agent, so hopefully awareness is increasing. Good reason to use a mono-only printer where possible.

Each of these leaks shows just how broken classified document handling in the USA is.

@SuperMoosie @vkc this is a toolkit that can do exactly that - https://github.com/dfd-tud/deda

@vkc Alternate solution, maybe: get 3 printers, print a bunch of tiny yellow dots randomly on two of them, then the actual document on the third.

Assuming the printers put the data in the same place every time, that should corrupt it, I'd imagine.

@mausmalone I was thinking something like that, but I'm imagining you need three of *the same model printer* in order to sufficiently deal with it. Alternatively the encoding might be robust enough to detect through that.

@vkc
Maybe becouse of that is why you can't print in black if you dont have color ink?

@vkc yes. as a privacy person, our personal opinion is that you should assume all modern printers have a system of this nature, although it hasn't been a focus of active research in some years

@vkc @ozzelot I would think it has tool marks that would be identifiable but not serial numbered.

@vkc Sometimes I want to make a CUPS compatible plotter using steppers and a bic pen.

@socketwench yes!!!!!

@vkc @ozzelot You can also just use a black and white laser printer instead of a color one...

@steter @vkc @Kiloku
When I was a kid my mom was a school teacher. She made her own mimeograph gel in a cookie sheet and printed handouts and tests for her classes. I’d help her with the very laborious printing, laying one sheet of paper down at a time and gently brushing the back of the sheet with a ruler. Then you peel it off and lay it down on the ping pong table.

@ireneista @vkc hmm, I keep thinking about replacing my printer that stopped working, so I don’t have to go to the shop and spend $5 every time I need to print something, but maybe I should stick with the shop printer

(As infrequently as I need to print things I’m probably saving money anyway)

@ShadSterling @vkc the shop for sure has a record of your legal identity as well, and since nobody has figured out what data is inside the steganography, it could plausibly include a timestamp. so, it's a valid option but don't make any strong assumptions about how safe you are or aren't.

@lebout2canap I only knew about it because it came up in the context of a court case where someone had been printing and mailing threatening letters to themself.

@vkc

@vkc Printing on some laser safe acetate can help to make the tracking dots fairly visible. Or at least, when I've been making a 3d printed badges, it's been pretty easy to see the blocks of dots covering the page.

@vkc I was there the day Seth Schoen figured this out, at the old EFF offices on Shotwell Street in the Mission.

@pluralistic @vkc that's really cool!

@vkc
I wonder if (some) 3d printers do the same.

By the way there are way there are ways to try identify single camera sensors:

Photo response non-uniformity - Wikipedia

(en.wikipedia.org)