Color laser printers have contained hidden surveillance technology since the mid-1980s. Xerox and Canon developed Machine Identification Code, a system of mi...
Only the dots in a certain place in a certain pattern are used to track the printer. Any other dots aren’t useful for that purpose and can be ignored. If you printed a solid block of yellow at the correct location, however, the tracking dots might be indistinguishable.
The wiki page says the pattern is repeated about 150 times on a standard page, so it is fault tolerant. In theory, a printer could also dynamically relocate them. To avoid regions of yellow. But if there was no dynamic reloc, then you could overwrite.
Wikipedia thinks you are onto something!
In 2018, scientists from TU Dresden developed and published a tool to extract and analyze the steganographic codes of a given color printer and subsequently to anonymize prints from that printer. The anonymization works by printing additional yellow dots on top of the printer’s tracking dots. The scientists made the software available to support whistleblowers in their efforts to publicize grievances.
Thinking more about your (and TU Dresden’s) idea, circumvention would be a nice ability to have as standard functionality in linux printer drivers.
I wonder if inkjets do this too. I have only heard it in the context of color lasers, and that’s all the wikipedia page says. But IDK why they wouldn’t also add it to inkjets.
Only the dots in a certain place in a certain pattern are used to track the printer. Any other dots aren’t useful for that purpose and can be ignored. If you printed a solid block of yellow at the correct location, however, the tracking dots might be indistinguishable.
That’s an interesting idea.
The wiki page says the pattern is repeated about 150 times on a standard page, so it is fault tolerant. In theory, a printer could also dynamically relocate them. To avoid regions of yellow. But if there was no dynamic reloc, then you could overwrite.
Wikipedia thinks you are onto something!
Thinking more about your (and TU Dresden’s) idea, circumvention would be a nice ability to have as standard functionality in linux printer drivers.
I wonder if inkjets do this too. I have only heard it in the context of color lasers, and that’s all the wikipedia page says. But IDK why they wouldn’t also add it to inkjets.