[<prev] [next>] [day] [month] [year] [list]
Message-ID: <51f007ff-b6bf-20d8-5a93-4d627be45142@bestmx.net>
Date: Tue, 14 Jun 2016 03:11:38 +0200
From: "e@...tmx.net" <e@...tmx.net>
To: passwords@...ts.openwall.com
Subject: A password is the ultimate form of biometrics
I have found today that passwords are the ultimate form of biometrics,
and here is why:
Fingers vs Fingerprints
It turned out that my "Authentication vs Identification" article was not
sufficiently conclusive in the sense that some hardcore biometrics fans
still nurture a non-trivial and well justified objection. So I need to
address and destroy it, in order to close the topic. My opponents'
argument is:
Your analysis narrows the both sides of the problem to a
knowledge/ownership claim. Even if you are right, the conclusion is only
applicable to the authentication by means of a knowledge token, whereas
all the rest relations between the user and the token (suitable for
authentication purposes) are set aside. There is one particularly
important relation (the one fundamental for the entire biometrics
field): "the user is" or other way around "the token is a part of the
user" -- this relation implies inalienability which makes the token safe
for authentication purposes.
It is true. Completely true. It is undeniably true! In the physical realm.
The trick is that this relation indeed implies inalienability of the
token, therefore it is not transferable. The very moment you scan my
biometric data the relation (you base your authentication upon) is
destroyed. A digital copy of my face is NOT a face and NOT mine either.
Since the moment this copy is taken I have no control over it. The very
reason of taking this copy was "my face belongs to me", but the copy
does not! -- you have lost the very relation you wanted to convey. This
is how in the digital realm all relations between me an my digital
assets reduce to the knowledge/ownership claims.
FOOTNOTE: Nor does this copy bear any information about other copies,
nor does this copy bear any information about its creation or any fact
of its past, where it has been, who have seen it, whether it is fake at
all... Still you can identify this copy with my actual face, no doubt
about it (the identification is not affected by that).
In the physical realm we have a whole bunch of tools to overcome this
limitation. We use human witnesses as a representation of a very complex
physical perception of the biometric data (although terribly faulty), we
use physical world's limitations to assess feasibility of falsification
the data, etc. All in all my fingerprints mean something to the police
only when they are made of body grease placed on a relevant item and
look reasonably "natural" -- a sheet of paper with my fingerprints drawn
in it has no value for a sane investigator.
-- Hey, I have found and old photocopy of some fingerprints! This must
be a suspect!
-- WAT?!
It is that in the digital realm there is absolutely no difference
between the "natural" fingerprints and the photocopies. This is the
world of photocopies.
But, we have reliable procedures to deal with physical evidence, can we
employ a machine to do the job? Yes, we can. What relation do we need to
establish? "The token is the part of the user" or more specifically "the
biometric data on the machine's sensors belongs to a living person". The
trouble is, the machine perception is way too narrow. Presented with a
human finger our machine can (in addition to scanning the picture)
measure the temperature, humidity, electric conductivity... but none of
these indicate a human being attached to this finger -- a bag of salt
could possess all these physical properties! EASILY!
In order to get some reliable readings we can create a very complex life
monitor that connects to all my vital organs, or we can use an existing
one -- MY BRAIN (which is, by the way, the most reliable life monitor in
the known universe -- zero chance of false-positive life reports).
Instead of connecting to my fingers, arms, legs, and other detachable
parts of my body, our machine can connect directly to my brain, by means
of English language. All we need to ensure the relation of bodily
integrity between my biometric data and myself (I remind you, this
relation is the foundation of the pro-biometrics argument) is to ask me
straight:
Dear user, are you sure the finger on my fingerprint scanner is
connected to your body?
"Gotcha!" -- you may say -- "how can you ensure the truthfulness of the
answer?". In a very easy and natural manner: we can beforehand agree
upon a secret obscure nondeductible answer, some sort of a code word...
Oh! wait!...
Powered by blists - more mailing lists
Confused about mailing lists and their use?
Read about mailing lists on Wikipedia
and check out these
guidelines on proper formatting of your messages.
