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It's pretty widely known (well, I think it's widely known) that printer manufacturers, in cooperation with certain governments, embed various bits of information (serial numbers, dates, etc.) in printed documents that can be used to identify the source, from the 90's at least to as recently as 2015. The EFF has studied this extensively and continues to do so. They had managed to crack Xerox codes around 2005 and released some source for decoding it.

In a recent conversation about the topic I realized that I could not think of a way to conveniently remove this information from printed output.

How can I protect my privacy in regards to documents I print? How can I defeat embedded identification data that printer manufacturers hide in the output?

Things I can think of are:

  • Don't use printers made by manufacturers known to do this. Unfortunately this is not a guarantee and also it rules out some really nice printers.
  • Smudge all printed documents with some sort of abrasive material. Highly inconvenient, damages documents, and I'd imagine there may be certain complicated techniques that this may not adequately counter.
  • Maybe include some sort of subtle background pattern in all printed documents? This does not seem guaranteed to be effective, though.
  • I also considered running documents through a photocopier, except nearly every copier I see now (including my own) is essentially a scanner + a printer, yielding the same problem in the copies.
  • Modifications to the printer's firmware and electronics are not a feasible option for many reasons, unless some sort of hacky printer mods already exist and are easily obtainable.
  • Always use somebody else's printer. I do not consider this an option; it defeats the purpose of owning a printer and also goes against my personal ethics.

None of these are particularly great.

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    How many pages do you intend to print without signature? Automatic ereasure of the signature might be necessary because manual ereasure is not feasible... – marstato Apr 5 '17 at 22:08
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    @marstato Any arbitrary number of pages, but in the single or low double digits in general. Not, like, 1000's. – Jason C Apr 5 '17 at 22:09
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    note this applies to color printers; there's no room to hide in B+W documents. might get a used cheapo B+W analog copier, or buy a used printer with cash on craigslist with a burner phone so it can't be traced back. If you live by a university, there will be several in the dumpster by the dorms/apts come move-out weekend... – dandavis Apr 6 '17 at 10:27
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    for color inkjets you can freeze the paper first so that the condensation microblurs it as it prints – dandavis Apr 6 '17 at 10:34
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    Buy 2 identical printers with cash, print top half of the page in one, bottom part in the other. Markings will create interference and ruin the fingerprint. – ThoriumBR Apr 9 '18 at 19:44
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First of all, your premise that all tracking is done via micro-dots is incorrect. Recent developments show that tracking technology uses micro-shifts in pixels or other invisible steganography-like technology to include tracking information into print outputs. So smudging or backgrounds won't really be a 100% solution.

You've lined up most available options, I'd like to add a few more:

Option [1] Most cheap inkjet printers can't do it due to the vast tolerances in head movement and cheap electronics. Use a really cheap inkjet with a custom ink feeding system (to get down the cost of printing to an acceptable level).

Option [2] For the really paranoid - build your own printer, there are several projects that provide 3D print blueprints for ink-jet printers, and electronics + software are open source.

Option [3] My sources tell me that most manufacturers only build tracking technology only into their high-end models (enterprise use mainly, since the original fear was that powerful laser printers can print counterfeit currency), and for models sold in the US. Suggest buying a lower end color laser printer from markets that are known with more relaxed regulations (or privacy concerns), e.g. Northern Europe/Scandinavian countries. No guarantees obviously there (unlike the first two options, but you will overcome the severe limitations in the first two options).

Option [4] Go green! Save trees, print less or use e-paper (e.g. Sony DPT-RP1/B Digital Paper). I know, may seem like a stupid option, plus e-papers come with their own problems.

Option [5] Get your printers from Craigslist or second hand markets. Don't ever connect them to the Internet. Change them frequently via Craigslist or flea markets. That way it would be extremely difficult for someone to find out who/where/what, or connect the dots.

BTW the backgrounds you were referring to are here: https://drive.google.com/drive/u/0/folders/0B9ZrovajUPg2U3Z2Ul9WSXI0b1U

Other relevant reading (Steganographix, 2013--2014. Steganographix Documentation): https://drive.google.com/drive/u/0/folders/0B9ZrovajUPg2NFEtNXZKUi02Tjg

Just my $0.02 :-)

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    Micro-shifts in pixels? You mean hiding data in the LSB? Although that's not uncommon for watermarking digital documents, for printers, I honestly find that pretty hard to believe. You are alsy incorrect that manufacturers only build tracking technology into high-end printers. It is done for virtually all laser jet printers, even low-end ones. – forest Apr 10 '18 at 1:24

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