Those rumours about colour laser printers putting hidden tracking codes in their output, at the behest of the Men In Black the government are true; a team of hackers led by the EFF have cracked the code used by Xerox printers, and are working on other manufacturers' codes:

The DocuColor series prints a rectangular grid of 15 by 8 miniscule yellow dots on every color page. The same grid is printed repeatedly over the entire page, but the repetitions of the grid are offset slightly from one another so that each grid is separated from the others. The grid is printed parallel to the edges of the page, and the offset of the grid from the edges of the page seems to vary. These dots encode up to 14 7-bit bytes of tracking information, plus row and column parity for error correction. Typically, about four of these bytes were unused (depending on printer model), giving 10 bytes of useful data. Below, we explain how to extract serial number, date, and time from these dots. Following the explanation, we implement the decoding process in an interactive computer program.

The reason this is an issue is because of the privacy implications of this technology. Yes, it can be useful for tracking down currency counterfeiters (as is its ostensible purpose), though it can (and undoubtedly will) also be used by oppressive regimes to trace dissidents. It's a lot easier than taking type samples from every typewriter, as the Soviets did.

Want to say something? Do so here.

Note to spammers: This comment system applies the rel=nofollow attribute to the poster's URL and all links. Posting links to this page will not improve their search engine rankings.

Display name:
URL:(optional)
To prove that you are not a bot, please enter the text in the image on the right in the field below it.

Your Comment:

Remember my details.

Please keep comments on topic and to the point. Inappropriate comments may be deleted.

Note that markup is stripped from comments; URLs will be automatically converted into links.