Date: Tue, 16 Aug 94 10:58:56 PDT
From: RISKS Forum <risks@csl.sri.com>

RISKS-LIST: RISKS-FORUM Digest  Tuesday 16 August 1994  Volume 16 : Issue 32

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Date: Mon, 15 Aug 1994 19:04:59 -0700
From: Phil Agre <pagre@ucsd.edu>
Subject: Desktop check forgery

  Saul Hansell, New breed of check forgers exploits desktop publishing, 
  *The New York Times*, 15 August 1994, pages A1, C3.

This article reports that it's easy to manufacture fake checks with widely
available desktop publishing software.  You need an original check, which you
can get from the trash, from a paid insider (usually a low-level employee), or
by standing outside check-cashing shops and paying people to let you photocopy
their payroll checks.  Then you need a scanner, and software to manipulate 
the image.  Then you need check paper and a check printer (both of which are
readily obtained).  Finally, you need someone to pass the check -- someone
who'll take a cut to risk getting arrested.

The forgers and the banks are engaged in a technological arms race.  Tellers
can run checks through scanners to make sure they've got the right kind of
magnetic ink on them, but then magnetic-ink printers are widely available.
Image manipulation programs allow for "authenticating" stamps and signatures
to be forged as well.  When forged checks are discovered, some banks fax 
the pertinent information to every other bank branch in the same region of 
the country, figuring that the forgers have made several copies of the check
and are driving around cashing them as fast as they can before the alarm is
sounded.  And so on.

This story illustrates one of the many subterranean interactions between
computer technology and social institutions -- the tendency of applied
computing to change physical objects into hybrid things that have one foot
planted in cyberspace.  We've always relied on the relative immutability of
physical objects to do various kinds of work for us.  Computers make it easier
to synthesize many kinds of objects, including mutated copies of originals.
The obvious solution -- at least, the solution that's obvious within the
conventions of computer design -- is to give every check a digital "shadow".
For example, when an employer issues a payroll check, the check number and
amount might be registered digitally and made available on a server.  When 
a check is presented for payment, the teller feeds the check into a scanner 
that recovers the check number and payment amount from the magnetic ink and
then, rather like credit cards now, consults that server to see if the check
has been presented yet.

This is only one of the many social mechanisms through which people, places,
and things acquire digital shadows.  Each mechanism has a seemingly inexorable
logic through which the shadows cast by human artifacts and activities grow
more expansive and more detailed.  This process might be planned out in
advance or it might proceed through a reaction to unanticipated holes in the
system.  When the trends that precipitate further growth in the shadow system
are bad, or at least stigmatized, little attention is paid to alternatives
that might minimize the amount of personal information that is being gathered
while still providing genuine benefits and helping to prevent genuine ills.

What's your shadow like?

Phil Agre, UCSD

  [The ability to cloud men's minds also helps.  But sniffing out forgeries 
  is itself an art: The Digital Shadow Nose!  <Shadowy laugh>  PGN]

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End of RISKS-FORUM Digest 16.32 
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