Reply to Eric

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.

>The description was run by the cryptanalysts for their comment.  

I've never seen any names, nor any statements of their analysis.  As
far as I'm concerned this stands as hearsay.

>The consensus was that the method was probably strong, or at least
>not obviously weak, but that they had insufficient information to
>judge properly.

Insufficient information??  And this is all you have for review?  Did
they even see code, or just an English description of it?  Look, if
saying they didn't laugh at it is digging your own grave, saying they
didn't even look at the full algorithm is acting as your own firing
squad.

>In-house testing has
>been as rigorous as we can make it, but any outside cryptanalyst is
>welcome to take a shot at it.

Anything as significant as a new cipher needs to be publically
examined before it can be trusted.  The opportunity for such public
examination is not sufficient, only the actual publication and
subsequent responses qualify.

Therefore, I have a challenge for you to submit your algorithm in full
detail to the public scrutiny of the academic cryptographic community.
You have unfortunately missed the deadline for papers for CRYPTO 93,
but you can always submit a paper to the Journal of Cryptology.  If
the cipher is to be considered secure, it should be proof against the
most sophisticated attacks known; currently this means that it should
be proof against differential cryptanalysis.

Until this kind of high-level review has been made, I openly and
publically recommend that this cipher not be used.

As far as a product goes, Dolphin Encrypt would be much more useful if
its cipher were trusted.  A rewrite to use triple DES would be
straighforward and would greatly increase the trustworthiness of the
product.

Eric