Subject: Delurking on Biometrics

From: "Zmudzinski, Tom" <[email-masked]>
Date: Mon, 29 Mar 1999 14:04:54 -0500

I've listened quietly and I know that this topic has come to an end.  But 
before it dies (actually it won't die, it'll just hide from the sunlight for
a while) 
I would like to throw in one point that is often forgotten when discussing 
biometrics, to wit: NOT EVERYONE HAS THEM.

Fingerprints?  Roughly 2% of the general population doesn't have readily
identifiable prints (BTW, 10% of those are doctors -- their fingertips
were scarred by repeated blood sampling when they went through medical
school).  And a very small percentage of the population is born without
fingerprints.  Ever shake hands with someone who doesn't have prints?
I have, and I can tell you it's past being slightly disconcerting!

Lip prints?  Well, let me mention this man ran into when I was selling
cookware door to door; he was a napalm victim who didn't have a FACE
-- once used to that fact and what it did to his speech, you'd find that
he still had a lightning wit -- and if he's still around I suspect he might
be 
listening to a talking computer.  Facial heat prints are the latest craze, 
partly because they can correctly differentiate so-called identical twins 
based on the fact that capillaries are grown in a fractal pattern.  The 
market hype claims that the pattern "never" changes -- even after facial 
surgery.  I'll reserve my opinion until I see the before-and-after bioscans 
of someone who has had their face stripped to the bone and rebuilt.

Retinal patterns?  Just because someone doesn't have eyes doesn't mean
they can't use a computer, a specially adapted one I'll admit.  See above.

DNA?  At the Army Medical Center at Fort Detrick, I once knew a man 
who was fraternal twins -- I don't mean he was *A* fraternal twin.  He has
different DNA in his hands and his feet.  He was a failed *SET* of twins!
The best the doctors could tell was that he had once been a pair of
fraternal zygotes that fused before they implanted in his mother's womb.

RNA?  We inherit it from our mothers (that's why my fraternal twin
friend has the same RNA, top and bottom, "both" of him had the same
mother), but RNA mutates every time we catch a virus.

The simple, unvarnished truth is that humans are colloidal lifeforms[*]
and there's nothing about us that is both universal and unchanging.

Tom Zmudzinski 

[*] We're jelly in the same sense as glass is a liquid.

"Reality is for people who can't handle science fiction."
            - variously attributed to Heinlein, Bradbury, or Asimov
"Trouble is, we're LIVING science fiction!" - me

---

From: "Bob Jueneman" <[email-masked]>
Date: Mon, 29 Mar 1999 15:09:07 -0700

Tom,

The points you raise are good ones. and even though the issue may 
be closed with respect to QC certificates, there are clearly lots and 
lots of people who are attracted to the promise of infallibility by 
biometrics who don't understand the problems.

Just a couple of clarifications, though.

1. Even though an individual may not have a _classifiable_ fingerprint using
the standard FBI classification technique, that fingerprint is almost surely 
identifiable as matching a previously enrolled sample, even if it is nothing 
but scar tissue.

2. Although I haven't investigated the field recently, the best 
fingerprint reader I am aware of as of three years ago was the Identix reader, 
which scans the finger using three different colors of LED, one of which 
is in the near infrared and "sees" the capillary pattern beneath the surface.  
Even if someone had no fingerprints at all, as I have heard claimed but 
haven't confirmed for bricklayers and those who might have had their 
prints removed by acid, I assume that they still have capillaries.

3.  I once attended a biometrics show that featured two vendors of retinal 
scan equipment.  One touted the advantages of retinal scans for 
biometric purposes, claiming that they were unalterable. The other claimed 
that they were excellent diagnostic tools, because of their ability to detect
changes due to diabetes, high blood pressure, etc.  Clearly they can't 
both be right, and knowing something about such illnesses, I'd bet on 
the diagnostic folks.

4.  Even the capillary pattern devices are subject to change, leading
to false rejections.  I once had an employee who flushed easily. If the 
fingerprint reader rejected his print, it would irritate him to the point where his
capillaries expanded, hence rejecting him all the more in a positive feedback.
Although as the system manager I ran the threshold for my own prints at a 
very high level, I had to lower his to well below the recommended level 
so he could get in consistently.

Bob

>>> "Zmudzinski, Tom" <[email-masked]> 03/29/99 12:04PM >>>

Tom Zmudzinski