DE-crypting (trivial case) (fwd)

[John K. Taber]

Forwarded message:
> From owner-cypherpunks at toad.com Tue Jun 21 09:14:10 1994
> From: dwomack at runner.utsa.edu (David L Womack)
> Message-Id: <9406211522.AA12298 at runner.utsa.edu>
> Subject: DE-crypting (trivial case)
> To: cypherpunks at toad.com
> Date: Tue, 21 Jun 1994 10:22:42 -0500 (CDT)
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> Fellow C'punks:
> 
> I was wondering if anyone knew of software that
> does decryption of weakly encrypted messages,
> i.e., similar to ROT13, but perhaps ROT(x) where
> 0<x<26?  Or maybe a bit more sophisticated, but
> not even at the single DES level?
> 
> Also...anyone know of any histogram software?
> i.e., I input a file, it counts how many
> letters of each type, and outputs it in a
> table and/or a graph?
> 
> If not, I'll have to (horrors!) write code!
> 
> Kindest regards,
> 
> Dave
> 
I have a hack in C for the PC that does trigraphic counting a la Sinkov.
It is just a hack, without documentation, and limited to a file that
is smaller than a 80x86 segment.  But if there is interest in it, I
can make it available.

Trigraphic counting, BTW, is the way to go.  Helps reveal repeated
sequences.  The same counting gives you your more normal stats too.