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New Technique Could Trace Documents By Printer
An anonymous reader submits "From this article at Purdue News, 'Researchers at Purdue University have developed a method that will enable authorities to trace documents to specific printers, a technique law-enforcement agencies could use to investigate counterfeiting, forgeries and homeland security matters.' The neat thing is that they are exploiting the characteristics of the print process itself to identify the printer." <update> One of the folks e-mailed me to say that the HP LaserJet 9000dn was one of the big ones tested with.
The problem here is many of the peices they would use to track the printers are integral parts of the replacable toner cartridges and printer ink kits. Only printers that have perm drums and heads will be easily traceable.
From TFA, the "fingerprinted" doc looks just like anything that comes out of my old DeskJet 693C ;)
I work for a large copier/network printer company (Not Brand X), and our machines have been able to do this for a very long time. A VERY tiny bar-code style serial number is placed everywhere in any printed and copied document (you need a microscope to see it).
This might be news because small desktop printers have never had small enough 'pixels' to keep it smaller then your eye can see.
"The price good men pay for indifference to public affairs is to be ruled by evil men." ~Plato (427-347 BC)
What about HP inkjet printers with the way they print from the cart? Toss it and do you have a "new" printer according to this kind of tracking?
I can see an emerging market in "stealth printers"(tm) if that happens. This is likely to go the way of the P4 serial number. -- nothing interesting here
About 15 years ago, I had an attorney do some work for me and he boasted about a software package he used that made small custom mutations to the font each document was printed in, such that once such a document was printed, it was very difficult for anyone to add or replace pages without being detectable as a later change to the original document.
Xerox (and others, I'm sure) have done this for quite some time.
About 5 or 6 years ago a friend that owned a print shop and used a Xerox color laser printer told me about Xerox imprinting every print with a watermark that could be decoded to obtain the serial number of the actual machine used in the printing.
The watermark was undetectable to the human eye and didn't alter the presentation of the image.
They did this at the behest of the government because it's so easy to print money on these things. This way they can track the money back to the machine via the serial number.
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So basically, they are saying if they had the original printer, and the document they could put the two together.
In order for this to provide the means to track a forged document to it's source will require printers to be "tested" when sold so their "printing fingerprint" can be recorded.
Otherwise, at best if can serve as a confirmation, not a tracing method. This is how ballistic characteristics test are used. They are used to confirm that a gun fired a bullet, not to trace the bullet to the gun.
My Suburban burns less gasoline than your Prius.
Wow! A plan to have traceable embedded signatures in all printers and resulting documents. Finally, a proposal for a government mandated way to trace all documents back to their creator. Remember it is for homeland security, so don't dare oppose this on the idea that it would chill free speech and decent. Besides, think of the children....Boy I feel safer already.
Really, I have to say this is a bad idea. The article goes beyond a forensic technique of trying to match documents to the printer that made it. They conclude that that is not possible in cases like ink jet printers with print heads on the replaceable ink cartridge so they propose embedding an "extrinsic signature" in all printers and printed documents. This would mean that every document printed would have a traceable signature; the protest letter you sent to congress, the art project you made with your kids, the protest flyer you posted on campus--everything.
The excuse for this new proposal is that it is for homeland security and preventing counterfeiting. But the broader truth of the matter is that this would be another nail in the coffin for free speech. Already, new police powers through the Patriot Act help make every posting on the Internet traceable. With the internet you have to connect from somewhere and almost all of the connections are logged.* Printed material was a way around this. Nobody could look at the paper and trace it back to you without some luck. You could write letters, post flyers and what not, and say what you liked. This proposed system would alter that landscape significantly.
Considering that there has not yet been a single conviction from the thousands of post 9/11 secret roundups, I'm reluctant to give our new found police state the benefit of the doubt.
*Yes, I know this is an over simplification.
Currency is printed by the fed, the biggest crook of all. And while the counterfeiters in Colombia and N. Korea do take a cut of the ill-gotten gains this way, and without permission at that, the crooks in charge trust them to not ruin it so completely that there is no wealth left to steal.
However, the fed can't have that same trust of joe sixpack, because he is an amateur crook, and might teach his buddies how to do the same. He is the biggest threat, and not to the economy... but rather to the scam itself.
If you bother writing your congressmen, add an extra sentence or two insisting that the government resume its right to coin money, and take it out of the hands of a private corporation owned by foreigners.
Things like this are troublesome, though:
One document obtained by the AP, a 1998 U.S. government business solicitation, mandated that "any color printer must include a tracing system that encodes system identification in any output. This will tie the output to the originating equipment so that forensic identification of the equipment is possible in the event of illegal printing of currency images due to failure or circumvention of the recognition system(s)...."
In a number of contracts where the US government has bought printers, they've required tracing features to be present-- effectively forcing them to be in printers sold to the general public as well. So effectively, many color printers are embedding their serial number in output documents. (And this is a lot more damaging-- saying this particular printer made a particular document, rather than a Epson Stylus 700).
"We will actually modify the way the printer puts marks on the paper," Chiu said. "This method is very difficult to get around because information about the internal workings of specific printers is not commonly available, even on the Internet." How long before this changes and people start soldering modchips into their printer circuitboards?
Nah, most politicians can't admit mistakes. That's why there's spin. It would be refreshing if just once a candidate would say "Hey, I was mistaken. I've taken another look and changed my position." Instead they have to pussy foot around and try to pretend that they were saying the same thing from day one.
Print it, fax it, copy it and then let them try to find the orginal printer.
If I'm really THAT into keeping my identity secret, I'll just print it out at some kiosk in a mall.
HexaByte - he's a square and a half!
I think they're taking the same approach to counterfeiting as Microsoft does to pirating. Microsoft stops Joe Schmoe from pirating by only allowing x number of installations per key. They still have XP Corporate edition which has no limit.
They know they're not going to stop the big-time guys, so they don't try. If you want to bad enough, there's nothing they can do to stop you (or even make it not worth your time). But they will stop the kid in high school who wants an easy $20. Maybe they're going after the wrong crowd, but everything is a trade-off.
The 9000 is the largest printer HP makes. It is very, very fast. Probably not as fast as some of the Xerox docucenters and such, but fast.
The problem is that people are stupid and don't actually examine cash they take. It used to be that cashiers could tell instantly if you handed them a fake bill, on feel alone. it's not like the US Mint and Secret Service haven't make efforts to tell people how to ID real currency...
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He told us this story (BTW, I have no idea if it is true.) about how all photocopiers in the USSR had a serial number etched on the glass so the copies it made could be traced. Much easier to track down papers proclaiming the joys of Liberty I guess.
Well, that teacher has past on but I really wonder what he'd think of all this? All kidding aside is the US starting to look a little like the old USSR?
"I hate to advocate drugs, alcohol, violence or insanity but they've always worked for me" - HST
Related to parent post because of the source: The Bush "Guard memos" are forgeries! The Hailey Connection
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Actually, this is more on topic than you might think. Somewhere in my library I have a U.S. Secret Service (propaganda) book from the 1950s about how they track down those that threaten the president and counterfeiters. In more than one example case given in this book they used specific characteristics of typewriters to track down letter writers. This has been largely impossible since the advent of non-mechanical personal printing techniques. Although, I disagree in the strongest terms with digital watermarking of this nature (and the Adobe ani-counterfeiting code for that matter) on the basis of privacy, it is interesting to note how this has been used in the past.