Printer Paranoia
“A research team led by the Electronic Frontier Foundation (EFF) recently broke the code behind tiny tracking dots that some color laser printers secretly hide in every document.” – [on slashdot|http://yro.slashdot.org/article.pl?sid=05/10/18/1210237&threshold=-1]
-break->
“We’ve found that the dots from at least one line of printers encode the date and time your document was printed, as well as the serial number of the printer”, said EFF Staff Technologist Seth David Schoen.
- [EFF press release|http://www.eff.org/news/archives/2005_10.php#004063]
- [EFF printer privacy site|http://www.eff.org/Privacy/printers/]
- [EFF: Xerox DocuColor Explained|http://www.eff.org/Privacy/printers/docucolor/]
- [EFF: (Un)Affected printers list|http://www.eff.org/Privacy/printers/list.php]
- [Support EFF|http://www.eff.org/support/]
The following thoughts are collected from Slashdot:
“Once the code is cracked, anyone can add a pattern of yellow dots that say anything. Assuming someone can tweeze the overlapping codes, they would discover that the document was printed 10/10/05 by printer 2721272 or 5/8/05 by printer 8798798 or 11/2/05 by printer 9813982, etc. If one can get the alignment right, one could even fill-in the printer’s native dot pattern so that all pages are printed on FF/FF/FF by printer FFFFFFF.”, [says G4from128k|http://yro.slashdot.org/comments.pl?sid=165632&cid=13816353].
“Also interesting is Andrew Bunnie’s [flat bed page scanner mod|http://www.bunniestudios.com/wordpress/?page_id=51] to use blue light instead of white. This made the yellow tracking dots easier to see, and the whole page could be seen at once to determine the pattern they made.”, [says morcheeba|http://yro.slashdot.org/comments.pl?sid=165632&cid=13816233].
“You’d think it would be easier to…
- A1. scan as normal
- A2. separate the channels into CMYK in Photoshop/whathaveyou
- A3. inspect the Yellow channel.
- B1. scan as normal
- B2. separate the channels into RGB in GIMP/whathaveyou
- B3. do a difference matte between the channels
- B4. inspect the result
- C1. replace the yellow toner cartridge with a black one
- C2a. stock the other holders with empty cartridges
- C2b. or if that causes a printer error/warning, block the cartridges’ output
- C3. print
- D1. get a sheet of blue filter plastic
- D2. scan through that”, [says Animaether|http://yro.slashdot.org/comments.pl?sid=165632&cid=13816313].
I like the overwrite-those-damned-codes idea the best, however it’s not the real solution, but a clever hack. But I fear the printer “is not allowed” to make a dot in the same size as the code-dot one.
Commenting is closed for this article.