EFF Cracks Xerox Fingerprinting Code

FormFactorFormFactor At the core of forgotten
edited November 2005 in Science & Tech
The Electronic Frontier Foundation has posted an article on how to pull the date, time, and printer serial number from forensic tracking codes in a Xerox DocuColor color laser printout.

The tracking codes are intended to be used to help law enforcement investigators solve crimes.
[img]http://www.short-media.com/images/newsimages/2005/October/xerox code.JPG[/img]
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.
Source: The Electronic Frontier Foundation

Comments

  • gtghmgtghm New
    edited October 2005
    I'm sorry if I fail to see the point... but why would we even care about such a thing?

    Just wondering? :wink:
    "g"
  • FormFactorFormFactor At the core of forgotten
    edited October 2005
    gtghm wrote:
    I'm sorry if I fail to see the point... but why would we even care about such a thing?

    Just wondering? :wink:
    "g"


    Some people got bent out of shape because they felt the fact that the printers were secretly recording information was an invasion of their privacy.

    The article sheds light on what exactly is being tracked, and how to find it.

    Probably more useful for those in a tin foil hat.
  • airbornflghtairbornflght Houston, TX Icrontian
    edited October 2005
    yeah, or if your in the counterfiting business, thats why they mainly started doing it. thats why i still use an injet printer, or the old laser printers.
  • RADARADA Apple Valley, CA Member
    edited October 2005
    FormFactor wrote:

    Probably more useful for those in a tin foil hat.


    DON"T TOUCH MY HAT!!!!! THE ALIEN-RUN FEDERAL LOCAL GOVERNMENT WILL BE ABLE TO READ MY THOUGHTS! :scratch::wtf:
  • primesuspectprimesuspect Beepin n' Boopin Detroit, MI Icrontian
    edited October 2005
    Don't get too excited about inkjets - they do it too. It's been well known to anyone in the digital printing industry for years that this has been going on. Images on the web are similarly encoded. It's called steganography. Put it this way - almost any image you see is encoded in some way with meta information - be it serial number of device that it's been through, originating device, date, time, etc.
  • TheSmJTheSmJ
    edited October 2005
    Yeah. So stop taking those kiddie-porn pics with your digital camera, k?
  • RWBRWB Icrontian
    edited October 2005
    TheSmJ wrote:
    Yeah. So stop taking those kiddie-porn pics with your digital camera, k?


    Yeah you take them with a disposable film camera and send them in to be made. That should protect your ass from any trouble :thumbsup:
  • ThraxThrax 🐌 Austin, TX Icrontian
    edited October 2005
    Right until you have to give your name and phone number so they can call you when it's ready. azn.gif
  • MizugoriMizugori NYC
    edited October 2005
    viva polaroid

    ...just kidding! jesus
  • airbornflghtairbornflght Houston, TX Icrontian
    edited October 2005
    I HAVE A SOLUTION!!!

    heres what ya do. scan a $20 bill and make like 500 prints of it. (do the back side too ya idiot)

    make sure ya print them on paper that mirrors the real stuff, then smash the printer into tiny bits and pieces.
  • MizugoriMizugori NYC
    edited October 2005
    actually you better burn those pieces into ashes then eat the ashes then crap outside and plant something in it... forensics these days, whew, you really gotta re-organize those atoms just to be safe

    or you could um, get a job.
  • primesuspectprimesuspect Beepin n' Boopin Detroit, MI Icrontian
    edited October 2005
    smbyte! ;D
  • airbornflghtairbornflght Houston, TX Icrontian
    edited November 2005
    he heh heh..i have a job, no wait. did./gonna ;D
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