Re: Jim Reed's Hagelin Cryptanalysis article

On Mon, 19 Mar 2007 22:41:50 +0000, Douglas A. Gwyn wrote:

Jeff Dege wrote:
... One poster described the paper thus:
Jim Reeds (with Dennis Ritchie and Robert Morris) wrote a paper in
1978 that applied what was essentially a fuzzy logic approach to
cryptanalysis of Hagelins, turning it into an eigenvalue problem.
The paper was not published,
Which suggests either that the details of this approach are known, or
that posters on USENET blow a lot of smoke.

It's not smoke; I have a copy of the paper.

You have to admit that there are a lot of people blowing smoke on USENET.
But your post from back in 2001 sounded as if you had some idea as to what
you were talking about.

Has this paper been made publicly available, anywhere? Seems to me
the
security concerns would no longer be relevant.

I'm fairly sure that the authors have not yet given permission for the
paper to be published. One of them rechecked several years later and
was told that its release was still inadvisable.

In another post, Greg Rose said that the paper was still classified.
Nothing in what I had read of it indicated that had ever been classified -
Ritchie's account describes its status as being somewhat more informal
than that.

The "security concern" is that the method is much more generally
applicable than to just the Hagelin, and since it has apparently not yet
been publicly described (beyond the vague sketch above), it provides the
people who do know it with a competitive edge.

I knew that was true in 1978. That doesn't mean that it was true today.
I'd hope that modern algorithms were designed to be resistant against it -
even though it's not been published, as DES was designed to be resistant
against differential cryptanalysis.

With respect to Wayne Barker's monograph on the Hagelin, Ritchie suggests
that Barker probably had access to Reeds' notes, but "missed their main
point". Is it possible that Barker understood "the main point," but kept
it private, for the same reasons that Reeds et al. had?

In any case, is there a better publicly-available source on cracking the
Hagelin than Barker's?

--
Nearly every electrical engineer believes deep in his heart that he
is better at writing computer software than any computer programmer,
and can show as proof the fact that he has written a number of small
applications, each of which was done quickly, easily, and exactly met
his needs.

.

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