How printers and Photoshop detect and refuse to process images of currency

http://www.cl.cam.ac.uk/~sjm217/projects/currency/

by kibwen • 13 years ago

191 115 13 years ago

cl.cam.ac.uk

leeoniya• 13 years ago

seems like something that can be bypassed by patching a couple jumps in asm with the help of IDA and a cup o' joe.

yapcguy• 13 years ago

GIMP... and enjoy the coffee.

BrownBuffalo• 13 years ago

Exactly. Why is anything useful done, has to be done on a *nix? Oh wait ... that's how things GET DONE.

aaronem5• 13 years ago

Well, yes. But then you have to use GIMP, which constitutes a punishment in its own right. ("...not a sin, but a penance.)

Genmutant• 13 years ago

At least for older versions of Photoshop there circulated currency-patchs so that you could edit money if you wanted to.

comex• 13 years ago

Perhaps more interestingly, the help of IDA could also determine what the code is actually doing in more detail than can be learned from the relatively crude black box methods in the link.

pionar• 13 years ago

When I was in college (99-2000ish, maybe?), one of my roommates was an art major with a graphic design bent, and he had this high end printer and would copy and print $1 bills and take 20 at a time over to the vending machines around the corner from our apartments once a week or so. After about a month of doing this, the machines disappeared.

Of course, he's the same roommate who later got arrested for wire fraud and grand theft.

twistedpair• 13 years ago

Given the cost of high quality ink and paper, one wonders how much less than $1 those bills cost to make.

aaronem5• 13 years ago

Given that it was a decade and a half ago, and that even today's vending machine recognizers probably don't do much beyond making sure a few relatively gross features are present, I doubt the cost per counterfeit was all that close to $1.

midas0073• 13 years ago

It's likely an economy-of-scale: bigger the operation, the better the ROI. Low volume would be expensive.

thirdsight3• 13 years ago

Similar. A friend of mine used an epson stylus printer (new on the market then) and a scanner to copy £20 notes. They were inserted into the change machine in the local gambling arcade type place. It was stupid enough to accept a single sided copy.

Out popped pound coins.

He now works for GCHQ which is funny.

Edit: just to add that these change machines were really naff and obviously built by the lowest bidder.

Zhenya2• 13 years ago

NAFF - At first I decided that it stood for 'Not Anything Fucking Fancy'

then I googled it and realized its british slang:'https://www.google.com/search?q=naff

dhughes• 13 years ago

It was stupid enough to accept a single sided copy.

DIP switches are set for various options one being accept face up (two-way), other options turn on or off acceptance of certain denomination bills and maintenance features such as calibration.

Even now modern acceptors allow this, although four-way acceptance is often preferred by the customer.

alextingle5• 13 years ago

He now works for GCHQ which is funny.

So he just moved on to even more serious crimes.

diogenescynic• 13 years ago

he had this high end printer and would copy and print $1 bills and take 20 at a time over to the vending machines

I'm embarassed to admit that in middle school my friend and I did something similar as his dad ran a printing business out of his garage. It surprised us then that this worked so easily. Luckily we only used them on vending machines and we quit doing it before we got caught. It makes me wonder what more sophisticated criminals can get away with.

erichurkman2• 13 years ago

It makes me wonder what more sophisticated criminals can get away with.

A lot. http://en.wikipedia.org/wiki/Superdollar

Theodores2• 13 years ago

If you have the criminal connections you can buy forged currency in a similar way to how you can buy drugs, the idea being that you can make a return on your investment if you put the work in to shift 'the product'.

Quality is a factor in the price so (for example) a bag of 100 £1 coins might cost £60 but you might not be able to use them in vending machines due to the weight being wrong. Notes again have their price depending on quality and cut.

gcb0• 13 years ago

This is the main point. anyone willing to commit the crime will find ways. it is just like TSA at airports. Those systems do nothing to actually prevent the crime.

it just fatten someones pockets who then pass a percentage down to the policy makers.

alan_cx• 13 years ago

I love to see figures on the size of the "being seen to be doing something" market. Im willing to be my entire fortune of 50 great british pence that its bigger than the video games market.

jasonkester• 13 years ago

In a similar vein, I remember a class trip on a Ferry from Seattle to Vancouver back in the 80s. There was a change machine that would give you four quarters for a dollar so that you could play video games.

It seemed smart, as it would give you the same four quarters if you used a Canadian Dollar or an American one. Or maybe not, as one kid found out when he stuck a $5 bill in and got 4 quarters.

Being 12, and therefore far more clever than the designers of this machine, the kids then proceeded to cut our a few thousand little rectangular strips of paper, roughly dollar sized, and clean that poor machine out.

And being 12, and having Ms PacMan machines as the only way of disposing of that giant sack of quarters, when it became apparent that there was no way to spend them fast enough, it naturally degenerated into a game of "Throw the quarter in the Ocean".

hatchoo• 13 years ago

When I was in the States, some buddies had some Philippine Peso coins which weigh and are roughly the same size as quarters. They used a few if these to operate coin-based laundry machines.

saalweachter2• 13 years ago

The best part about this is, in small numbers, foreign currency just becomes domestic currency on the basis of similar appearance alone. You get a Canadian penny, you may not even notice, and even if you do, you don't care because the next guy won't either.

The laundry/vending machines are an interesting case because there's a decent chance that the the vendors would just be taking bags of coins to the bank where, presumably, the Pesos would be kicked out correctly. Even then, if there were only a small number of pesos, they probably just passed them on at someone else's vending machine, or in other cash person-to-person transactions.

It's hilarious to me that, while you can argue about what currencies are backed by, at the end of the day all that matters is that something spends. If something spends like a quarter, it's a quarter.

X42• 13 years ago

So much details on a note makes me wonder, if a message could be steganographed within notes.

Something like: If you can see this: Call 1-800-FED

nappy-doo16• 13 years ago

Fun fact: The treasury department won't tell you what is actually on the bills. In fact, none of the governments will. You can analyze them till you're blue in the face, under whatever light or circumstances you want, but the treasury department won't tell you what security measures are on the bill, nor when they change them. Additionally, they sometimes change during print runs, and issues.

dsl2• 13 years ago

Fun fact: you are asking the wrong branch of the government.

The Secret Service will happily tell you about security features of currency, and behind closed doors help you build methods to detect counterfeits if you have a reasonable justification.

http://www.secretservice.gov/know_your_money.shtml

dangrossman• 13 years ago

the treasury department won't tell you what security measures are on the bill, nor when they change them

Here are a few Treasury Department webpages telling you what security measures are on the bill, and they publish a press release with a new interactive site when they change them:

http://www.newmoney.gov/newmoney/flash/interactive100/index....

http://www.newmoney.gov/uscurrency/redesigned100.htm

http://www.moneyfactory.gov/anticounterfeiting/securityfeatu...

wyager2• 13 years ago

This is one of the things that made me really see the value of free software.

I did verify experimentally that the Eurion constellation alone doesn't trigger photoshop's image rejection algorithm. I think it would be fun to distribute a bunch of images that false-positive the digimarc algorithms, just to mess with people.

Zikes• 13 years ago

That sounds like a decent addition to watermarking. It'd be difficult to crop out a watermark if you can't open the image in an image editor.

MasterScrat• 13 years ago

There's actually a nice service to build here: "invisible watermarking" for photographers and designers...

chc• 13 years ago

I very much doubt there is any way you could do this with arbitrary images without completely destroying them.

logfromblammo2• 13 years ago

They could add the detection to GIMP. But then that would reveal what the algorithm is. And that would allow specific strategies for producing false negatives or false positives.

I'm still undecided about whether countermeasures to reverse engineering like this are useful or not in the long run.

w1ntermute• 13 years ago

Adding it to GIMP would be useless, because it would be trivial to produce a patch to disable the functionality.

atmosx2• 13 years ago

These measures can stop a kid from counterfeiting. That's all they do. I'm sure in the process they could create some kind of sporadic troubles to designers which paid for the expensive software.

You can't possibly think that a criminal organization, with average tech resources, will have a hard time getting around this in a way or another.

sliverstorm2• 13 years ago

This is one of the things that made me really see the value of free software.

How do you mean? Is there much (legal) value to be had from image software that can process accurate scans of currency? I'm just kind of confused here, what value you speak of.

t0mas88• 13 years ago

See below for example: "When I used to make news graphics for a tv station, every now and then this problem in Photoshop would arise and it was incredibly annoying to make anything with a flat dollar bill as part of the background."

wyager2• 13 years ago

Because my software should never tell me that I can't do something for non-technical reasons. Assuming I'm a criminal is wrong. If I was a criminal, breaking the law is my decision, and my software should not impede my ability to do so.

Timmmmbob• 13 years ago

"Ah! I remember reading the original web page from years and years ago about the fact that this happens. I wonder if they've discovered how they do it now (the algorithm). I will click on this presumably new (on a news site) link that says 'how'. WTF? It's just the same old page from 2004!"

krapp2• 13 years ago

When I used to make news graphics for a tv station, every now and then this problem in Photoshop would arise and it was incredibly annoying to make anything with a flat dollar bill as part of the background.

whoopdedo• 13 years ago

In the distortion samples, the uri for orig.png redirects to a non-existent server.

MyNameIsMK• 13 years ago

If this software is detecting currency, the obvious follow-up question we should ask is: what else is it detecting, how does it do this, and why?

Could it be that each image generated from Adobe Software also tags the image with unique identifying computer, timestamp information?

krapp2• 13 years ago

Given that Adobe is attempting to move their software over to their Creative Cloud service, then that is probably quite possible now.

Beyond that, I think the bigger threat to privacy by far in digital images is in EXIF data and reverse image searches.

X42• 13 years ago

Yup, that + what happens when it crashes? I wonder, if a network packet is sent somewhere.

cheeseprocedure• 13 years ago

On a related note: many colour printers leave a tiny encoded pattern on each page (based on model/serial/etc), ostensibly to help track counterfeiters. [1] [2]

Unfortunately, they're printed all the time.

[1] https://www.eff.org/pages/list-printers-which-do-or-do-not-d...

[2] https://www.eff.org/issues/printers

aestra• 13 years ago

Perhaps also for forensics in case of other crimes as well.

alextingle5• 13 years ago

The main use is to identify leakers.

ChikkaChiChi• 13 years ago

What bothered me in the other thread where I first learned this is that while I have always understood that I don't have a reasonable expectation of privacy on the Internet, I feel dirty as shit when I realize my computer determines when something is legal or not for me to do.

Slippery slope, this one.

blah32497• 13 years ago

Does anyone have any insight into why Adobe and printer companies actually care about this? Are they being paid to do it by the secret service? (and wouldn't that be public information?)

Theodores2• 13 years ago

Digimarc wrote the software for the Central Bank Counterfeit Deterrence Group. News of this was reported in 2004:

http://news.cnet.com/2100-1012-5138816.html

joering2• 13 years ago

If you were living under the rock for last 6 months then I will answer you: no, it won't be public information, as most likely NSA/CIA/whomever surely would like you to print some notes, so they can catch you. So Adobe/others have a gag order/if any not to speak about the subject.

I would however think that they do that simply to protect themselves in case so that noone will come after them legally that they allowed counterfeit to happen (so easily). Sure you can always trick the machine/software, but hey at least Adobe did try to stop you so they do "work" in a good faith.

I once watched a documentary on counterfeits and it seems it would costs about $80 to produce a perfectly looking, no-difference $100 bill using the latest technology. Noone will ever attest its fake other than Federal Reserve, and thats only because they have never produced a note with this serial #. The real game, supposedly, is not in producing fake notes that pass all tests; the real "problem" is how you put enough number of bills in the circulation so that #1 you make plenty of money, and #2 you don't get noticed/caught.

Surprisingly, the price for a perfectly-fake bill is not going much higher than $80, and as the rumor goes, FedRe stopped producing $1,000 bills for this exact reason.

midas0073• 13 years ago

Most color printers print their serial number on every page to assist in identification of forgeries.

https://en.wikipedia.org/wiki/Printer_steganography

aortega• 13 years ago

The algorithm that the author is painfully searching by brute-forcing a picture is hidden by simply compilation. Decompilation of a binary was hard in the 20th century, not so much now. Discovering the exact algorithm only requires some time and some skills.

elliottcarlson• 13 years ago

This has been around for a lot longer then the article (from 2009) suggests. High end publishing printers had a lock-down mechanism built in as early as the late 90's when you attempted to print US currency.

As mentioned in this comment thread, there is a general description of the security features on newmoney.gov - while I was working on the original version of newmoney.gov for the release of the new $20 bill, we were given high DPI scans of the new bill and were only allowed to make low DPI, specific crops - all while in a "war room" that did not have internet access nor were we allowed to bring in any cameras or cellphones.

Some interesting little facts I was told while working with the BEP: most counterfeits are actually done by other countries with proper currency printing machines. Small time counterfeiting is generally bleached out $1 bills printed over with $5 images to retain the same cotton-paper ratio used so that it feels the same.

ironmanjakarta• 13 years ago

Yeah, gotta stop those evil counterfeiters. But not the Fed. Even though they've counterfeited 100s of trillions over the last 100 years. :P

How printers and Photoshop detect and refuse to process images of currency

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