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Hidden Codes in Printers Cracked
r84x writes "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.
The U.S. Secret Service admitted that the tracking information is part of a deal struck with selected color laser printer manufacturers, ostensibly to identify counterfeiters. However, the nature of the private information encoded in each document was not previously known.
"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."
For those interested in a quick summary, the docucolor example is the best place to look. (it has pictures!)
More information can be found on the EFF's printer-privacy webpage.
Also interesting is Andrew Bunnie's flat bed page scanner mod 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.
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do you really think that "they" have a database they could reference to find out what printer serial number goes to what citizen?
Most laser printers are rather expensive items. If you paid with a credit card, then yes, they have it in a database. (All stores record the serial number of high-ticket items they sell. I've actually gotten recall notices this way, so I know the store shares it with the manufactorer.) Even if you paid in cash, if you filled in the warranty card, they have it. Got a mail-in rebate? On file. Ever had to have it serviced? You're on file.
Speaking as a trained Xerox Docu* operator who can recite his DEEZEROCEE serials in his sleep.....
The DocuColor printers in question are very high end printer/copiers that are installed and maintained by trained technicians known by Xerox as Customer Service Engineers or CSEs. When it breaks or needs parts, you call your CSE. Think "on-site support" but on steroids. You pay a ton for this.
The system clock is set by the installer CSE and possibly updated as needed on subsequent service calls, and there are MANY of those as DocuColors require frequent maintenance and upkeep. It is not uncommon to have service once a week for some models. Or worse. They can be touchy beasts. The machines, I mean. The CSEs can be your pal or your worst nightmare. I like the ones my bosses hate. Go fig.
So what is the clock for? Among other things, time stamps are used by the printshop for tracking when every single print was made including which operator made it. So no more late night "free copies" for your pals. Xerox also uses the logs for all sorts of legit reasons. Nothing evil there.
So what about resetting the clock? First you'd have to get the machine open. This is not like a computer with handy access panels and common PCBs, er, that's PWBs in Xerox-speak. You'd have to know the machine inside-out, have the tools and the skill to take it apart (God help you), and hope that the battery is resettable rather that buried inside a chip. Xerox is very, very aware of people trying to cheat the machine meters to make free copies so stuff like counters and clocks are already armored and protected from prying hands.
Assuming you managed to do all those things and got the machine back together, then it has to be recalibrated because taking it apart will have wrecked the system setup. So you have to call your CSE, who resets the clock straight away, probably by pushing the keys with the bones he removed from your hands for messing with his machine. If you're still alive at this point, you are right back where you started!
Side notes: the vast majority of DocuColors are leased out by Xerox rather than sold, so the machine is normally Xerox property from assembly to reman to reman to reman to junkyard. Why? Some of them can cost half a million and up for new, less for used, but either way these are not something people "buy" when they can simply lease. GE Credit is happy to finance the leases and end users find it much cheaper and they don't end up stuck with obsolete machines.
Many of the older machines can and do end up on the sale market and it is possible to buy one and own it, but it will still require service (lots for an old machine), toner, supplies, parts, and preventive maintenance. Xerox controls almost all the DocuColor parts, supplies, ink, and most of the trained CSEs so you pretty much have no choice but to sign on for a Xerox service contract even when you own the thing free and clear.
Yes, there ARE trained key operators who can get in and do SOME maintenance chores but only Xerox can get parts and has the technical knowledge to use them.
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Quite frankly, you have no idea what you are talking about. I work in high-end color, and all of our toner devices have this encoding technology. I have talked to plenty of people in the industry, who sell these machines. They are required, by law, to record the serial number and purchaser of every such device. Furthermore, they are required by law to record the sale of any electronic part used in these devices, and yes, all the boards are individually keyed to the serial number of the device. Swap boards with another device, and the machine stops functioning.
This is also true of the mid-range color laser printers you purchase at your local Best Buy or Micro Center. In fact, if you open your eyes at the checkout and actually pay attention, you would notice that after they scan the bar-code, their register prompts them to either scan the serial number bar-code, or hand-key in the serial number. Now, they may not be required to record your name and address, but they most certainly can trace it back to your credit card.
The whole point of this is to catch counterfeiters. It's useless to know the serial-number of a device if you don't know where it was sold.
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