Subject: PKIX non-repudiation

From: Ed Gerck <[email-masked]>
Date: Mon, 06 Sep 1999 17:37:35 -0700

List:

It might be useful to view what others have understood
from  the X.509v2-3 and PKIX RFC 2459 definitions of
"non-repudiation", in order to see what was conveyed
by those texts -- before changes are introduced.  By
refering to "the reader's eyes" so to say, as reflected in
spontaneous renderings by those readers of what they
read in the specs, we can grade the specs' objectivity by
a metric based on neutral observers.

This is what I found in http://www.rmionline.com/cryp_tutorialbody
under "Electronic Crypto Method" for "Non-Repudiation":

 Digital non-repudiation is provided via digital signatures,
 which are created by hashing a  message (file) and encrypting
 the result with the private key of  the authorizer. This binds the
 digital signature to the digital message (file) being authorized,
  making it extremely difficult to counterfeit.

which means that, to them, "non-repudiation" is directly provided
by the security of digital signatures.  It is a syntactic property of
a digital signature by itself.  The fact that this WG has recently
unanimously rejected this interpretation even for what has been
called here "technical non-repudiation" is an indication, IMO,
that this rendering should be denied in future documents in
order to clarify what NR is not.

{In other words, what is being described in the reference is simply a
property of DS, not a property of NR}

Further, even though it might not be yet so clear to this WG what
NR is or should be in PKIX, we may have achieved a better understanding
of what NR is not -- and this could likewise be reflected in the specs,
in order to avoid future false interpretations.  Counter-examples help, also
in specs.

Cheers,

Ed Gerck

PS: BTW, the same reference has also a rather fitting acronym for
that which discussing these matters may potentially produce ;-)

 The primary components of transactions security can be remembered
 by their acronym, PAIN, and include:

     Privacy (P)
     Authentication (A)
     Integrity (I)
     Non-repudiation (N)

---

From: Stephen Kent <[email-masked]>
Date: Tue, 7 Sep 1999 17:33:07 -0400

Ed,

>a metric based on neutral observers.

There are lots of folks writing about PKIs, NR, etc. who don't necessarily
know what they are talking about.  We see this often, in a variety of
venues.  While it is worthwhile to try to clarify our definitions, I would
not measure our success by what we see written by these folks, e.g., in
online, unreviewed documents, trade magazines, etc.  Still, I agree that it
may be worthwhile noting how people have misunderstood what we and others
are saying, and use that as input to examples, but even here one cannot
cover all the "wrong" bases.

Steve

---

From: Ed Gerck <[email-masked]>
Date: Tue, 07 Sep 1999 15:45:13 -0700

> cover all the "wrong" bases.

Clearly not, nor I implied so.  But, as you agree, as a useful tool.  Especially,
to know what the policy-makers and the lawyers can understand ;-) or not.

Cheers,

Ed Gerck