Take a look at that dollar, Euro, yen, pound or peso in your
wallet. Is it real or counterfeit? How can you be sure?
Counterfeiting used to be the domain of skilled criminals
with expensive engraving and printing equipment. Not so today,
thanks to advances in computer and printing technologies that
have dramatically reduced the cost and difficulty of reproducing
Not surprisingly, that's unsettling to a company like HP.
That's why researchers at HP Labs and experts from the company's
printing and imaging business got together at the request
of U.S. and international officials to help clamp down on
"As the world's largest printing and imaging company,
it was important to us to lead the industry in this area,"
says George Lynch, Director of Strategic Technology for HP's
Imaging and Printing Business.
A growing problem
In 1995, less than two percent of counterfeit money in the
U.S. was produced electronically, according the U.S. Secret
Service. Last year, counterfeiters turned out $44 million
in U.S. currency -- nearly 40 percent of it using digital
equipment like color copies, scanners and ink jet printers.
The U.S. greenback, the world's most popular currency, is
also the most counterfeited because it is so universally accepted.
"There's a lot at stake," says Neerja Raman, director
of the Imaging Systems Lab at HP Labs. "If we want the
world to continue to have faith in U.S. currency, we at HP
have to have a zero-tolerance policy for counterfeiting."
Preventing fakes while protecting image quality
Lynch, Raman and many others at HP put their considerable
imaging expertise to work, collaborating with officials and
technical teams from various public- and private-sector organizations.
(The names of these organizations must remain confidential).
The challenge: find a way to prevent the reproduction of
U.S. banknotes on home equipment without affecting the quality
or the print speed of everything else.
"We had to have a solution that was inexpensive, and it had to be
unobtrusive," says HP Labs researcher Henry Sang. "Nobody's
going to pay an extra $50 for a printer because it prevents
counterfeiting, and they're not going to buy one that won't
print green or that prints three times slower because it's
trying to detect a counterfeit."
Challenges and constraints
Until the 1990s, when the U.S. Bureau of Engraving and Printing
added new security measures such as a watermark and a security
thread, U.S. banknotes had changed little for decades. Federal
officials told the HP team they wanted to keep it that way.
That precluded any major changes to the currency itself,
including techniques used by some other currencies. The Euro,
for example, contains fluorescent fibers and foil features,
which cannot easily be reproduced by conventional copiers
To recommend how to best approach the problem, the R&D team
first had to learn more about how currency was being counterfeited,
then determine ways to prevent it. For example, it's possible
to give a scanner the ability to detect when it's scanning
a $20 bill. But it's also possible to find a high-quality,
printable image of a $20 bill on the Internet, or to take
a digital photograph of it, so just blocking the scanner won't
totally eliminate counterfeiting.
Another challenge: Most people can't identify a counterfeit
bill. Sang says federal officials showed him one-sided bills
and even black and white bills that had been passed.
"Counterfeits don't have to be good enough to be undetectable
by the government or by banks. They just have to be good enough
to be passed from person to person," he says. "By the time
you pass it to a store clerk and the store takes it to the
bank and the bank is able to detect it, the criminal is long
Detection and deterrence
So, what could be done? The team attacked four key issues:
Can the bill be passed? Can we detect counterfeiting intrusions
on low-cost machines? Can we prevent the printing of counterfeit
bills? Can we we help authorities who have to prosecute the criminal who produced the bills?
Researchers came up with a host of recommendations, applying
technical knowledge in image processing, color management
and information embedding to devise several counterfeit deterrence
Although they cannot disclose exactly what or whose technologies
federal officials finally adopted -- at the risk of tipping
off criminals -- team members made suggestions for a wide
range of techniques for document and hardware design to thwart
"We made recommendations for a range of tests and procedures,"
Measures HP suggested include:
- Multi-level detection and deterrence - a detection scheme
that uses an algorithm to separate suspicious documents
from those free of suspicion. Additional, more complex algorithms
determine if the suspicious document is a "secure"
one that's likely to be currency, and then either provide
a "selectively deteriorated" print or disable
printing of that document completely.
- Two-sided documents - This technique takes advantage of
the front-to-back registration accuracy of HP printers by
changing the position of objects an infinitesimal amount,
too little to be seen by most people, but enough so that
a machine can detect it.
- Color detection - This is a key technology because humans
are very good at detecting differences in color. This technique
would detect the characteristic color of frequently counterfeited
documents ("banknote green"). Were a user to attempt
to print a banknote using the exact green in the correct
density for a bill, the printer could modulate the color
somewhat to produce distinct, visible bands of color. The
change in the color wouldn't be visible in other images
that use lots of green (photos of trees, for example), but
would be evident in bills.
- Printer identification - Researchers provided data on
how officials could better measure properties of a counterfeit
to identify what kind of printer and ink may have been used
to produce it.
- Government lab - The R&D team developed a proposal
for a laboratory the federal government could establish
to continue research into anti-counterfeiting technologies.
In May 2003 U.S. officials announced a radical new design
for the $20 bill that includes several new, confidential counterfeit-deterrence
features. These measures include adding light shades of blue,
peach and green to the $20 bill as an anti-counterfeiting
measure. (Note: The peach bills premiered in October 2003).
Printing and imaging expertise
HP was able to respond as quickly as it did to counterfeiting
concerns in part because of HP Labs' deep expertise and continued
research in imaging and printing. In addition, HP's imaging
and printing business made the effort to integrate anti-counterfeiting
measures into devices to demonstrate how these techniques
"Hewlett-Packard and its employees have
been clear leaders in our work with the printer
O'Neill, then-Secretary of the U.S. Treasury Department,
said in a letter to HP executive. "HP employees
involved in this work have been innovative and
professional, and a credit to your company."
Of course, HP isn't going into the currency-printing business,
but the company has used its experience to pursue new research
in secure printing and imaging.
A team in the Imaging System Lab has been working on ways
to embed information in printed documents for authentication,
security and other purposes, called "Graphical Barcodes."
In one application, users might be able to print authenticable,
customized postage stamps with a company logo, personal initial
or other image that contains the same information that an
ordinary bar code would.
Another application of the Graphical Barcode injects a "digital
life" into printed documents. When a document is printed
with a graphical barcode, the barcode contains all the information
about this document including its digital source. So when
the document is to be copied, instead of producing its photographic
image, the original document is retrieved from the digital
source and printed.
"Fax back" and authentication
This technology can also enable "fax back." A document
containing an information-embedded image (a logo, for instance)
is faxed to a recipient. The recipient can write on it for
reply. Because of the embedded information, the recipient
can fax it back without even dialing the phone number because
the fax machine recognizes that it is a "fax back"
document by the Graphical Barcode.
This technology can also be used for authenticating hardcopy
documents like a diploma, a birth certificate and a land deed,
etc. The information-embedding logo on the document contains
all the critical information that cannot be tampered with
"Almost any anti-counterfeiting technology can be defeated,"
says Sang. "The challenge for us is to make it that much
harder to do it."
by Jamie Beckett