From: meyer <wixer!wixer.bga.com!meyer@cactus.org>
Date: Fri, 28 May 93 21:34:48 PDT
To: cypherpunks@toad.com
Subject: Reply to Eric
Message-ID: <9305281746.AA11286@wixer>
MIME-Version: 1.0
Content-Type: text/plain



Eric Hughes writes:

>>It has also been examined by four cryptologists (professional and/or
>>credentialed) not involved in its development, and it was ridiculed
>>by none of them.
>
>I hear the sounds of autonecrothaphty (digging one's own grave).  Was
>it recommended by any of them, and did any of the test it?

It's true I'm going out on a limb here, but the potential benefit to
the world is a new cryptosystem of some value (a deliberately modest
claim).  And one that was not designed by NSA complete with
trapdoors.  Anything new always meets with resistance.

The description was run by the cryptanalysts for their comment.  The
consensus was that the method was probably strong, or at least not
obviously weak, but that they had insufficient information to judge
properly.  You may disagree.  You may not like the proposed method,
but the real question is whether it works.  In-house testing has
been as rigorous as we can make it, but any outside cryptanalyst is
welcome to take a shot at it.

>>The first task of a cryptanalyst
>>is to discover what method of encryption was used.
>
>Usually not.  This often comes as collateral information related to
>the intercept.  In the case of a PC seizure, having a manual lying
>around and an executable on the disk usually qualifies.

Yes, a cryptanalyst looks around for other evidence as to which
cryptosystem was used before the hard work of analysing ciphertext.
As you say, it may be a manual or an exmcttable.  The encipherer
himself may reveal it.  But in any case, identifying the encryption
method *is* the first step in cryptanalysis.