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.