Date:	Fri, 12 Jan 90 03:26:00 EST
From:	"Robyn Robertson" <GSRLR@alaska.bitnet>
Subject: Computer Generated Document Forgery: A Response

>The whole issue of security problems from scanners and laser writers
>has already arisen with Xerox machines; cutting and pasting a signature
>can be done using that technology by anyone owning scissors and white-out!

I agree that this approach to forgery has existed for some time, but the
generation of acceptable technically precise forgeries via this method
has required some degree of artistic expertise to accomplish.  If you doubt
this, by all means, attempt to generate a high resolution paste up using
these tools. It can be done, certainly, but the generation of high
resolution copy from this technique depends upon either extraordinary luck,
or the use  of such tools as an angled mat-cutter to facilitate elimination
of final copy shadow-lines from the pasting, repositionable/temporary
spray-adhesives to facilitate generation of wrinkle-free paste-ups, or the
use of graduated-photo-responsive lithography photographic media and
darkroom.  It may be that there are technologies of forgery with which I am
unfamiliar, but I remain convinced that the threat from computerized forgery
is at least several orders of magnitude greater than that posed by the
current popular forgery techniques.

On the other hand, I did once meet a woman with a great fondness for opiates
who managed this 'affection' with prescriptions she worked up using film-
type rub-on transfer letters.  She would lay out a prescription blank on
high quality posterboard, designing the entire form herself.  She generated
the prescription blanks in names of doctors that she had DEA(Drug
Enforcement Administration) identity numbers for(In this country,
prescriptions written for Schedule II drugs, i.e. drugs w/ a high abuse
potential like morphine and Dilaudid, as well as the pervasive cocaine).
the prescriptions were accurate to all detail aside from the telephone
number for the forged 'dispensing physician's' office.  In this spot, she
filled in a telephone number for a conveniently located phone booth where
she waited to intercept the call from the suspicious pharmacist wishing to
confirm the legitimacy of the drug order.  A confederate would enter the
pharmacy and present the prescription to the pharmacist.

The flaw in this technique was that the signatures attributed to the
prescribing physician were successfully subjected to graphological analysis,
and eventually the woman was convicted on the basis of this evidence.

Now, had the woman merely photocopied a valid prescription, the date would
have eventually given her away.  On the other hand, though the woman was
obviously modestly creative, and possessed of some artistic skills, she did
not attempt the obvious ploy of using a strong bleach to remove the date
from the valid prescription, then filling in dates on the production run of
the blanks proper.  I believe that this was due to the delicate nature of
the operation of bleaching and reprinting a master blank.  I urge that
anyone doubting this, attempt the operation...I watched the procedure
being done on a U.S. passport several years ago, and controlling
erradication of the passport's initial data without discolouring or
otherwise compromising the technical art of the resulting forgery, is no
simple feat.

Had this person access to even a mid range personal computer, scanner and
laser printer, I think that the case ultimately would have gone
unprosecuted.  In no event, could the forger have been tied to the writing
on the prescriptions she generated, by a graphologist, and assuming that she
took the elementary precaution of keeping her forgery files DES encrypted,
I believe she would have been beyond even arrest.  Certainly, no state or
local police department is going to be able to open a DES encrypted file in
order to present the material in court, and even if they could open the
cryptogram, there would be a very strong defense that the supposed
incriminating files entered as evidence were mere artifacts of the computer
process used to decrypt them...at very least, the case would ultimately
devolve to an argument over the significance of expert testimony describing
the connection between the decrypted evidence files, and the original
coded sources.  Think of it:  documents that take ten minutes work to
generate, and which have exceptional precision in all respects where visual
inspection, even fine visual inspection, is concerned, except where the
quality of scribe-impression weight is concerned.  These forgeries would be
generated on a relatively inexpensive set of devices, and would be based on
files that would be largely unaccessible to authorities.  This is a problem
much more difficult to contend with than the currently common approaches to
forgery.

As a final note, assume that a forger of prescriptions fills them only in
rural areas where the technology of computer forgery has not even likely
been entertained by authorities?  In such an environment, there might be
enough confusion generated by even detected forgeries generated via this
method, born of the accuracy of the forgery and lack of understanding of any
technology that could produce such a forgery, that the culprit might well
go unidentified and unprosecuted.

(Oh, the woman I mention above was filling prescriptions for a drug called
methylphenidate(Ritalin) used to treat minimal brain dysfunction in
children...viz. 'hyperactivity'.  Customarily, she spend about fifty dollars
for the first forged prescription, and about thirty dollars for each one
after that in a given production run.  Each investment resulted in the
acquisition of one hundred of the 20mg. tablets.  These, she split at a
ratio of 67:33 with her crew(the operation used three people in addition to
the planner; one to take the prescription into the pharmacy, one to monitor
the situation inside the store via VHF radio communication with the planner
awaiting the pharmacist's call at the selected phone booth, and one to block
pursuit if a problem developed in the store(by 'inadvertently' getting in
the way of pursuit...), or to present at the prescription counter(ostensibly
to purchase some OTC compound or other)immediately after the crime in order
to monitor the pharmacist's behaviour, allowing generation of a solid
follow-up report.   The woman then sold the methylphenidate tablets for
between ten and fifteen dollars each which users then disolved in water and
injected, leading to a worste-case income for a few hours work of over 600
dollars.  She then spent the resulting cash on heroin.

R. Robertson
BITNET: GSRLR@ALASKA
Internet: gsrlr@acad3.fai.alaska.edu