🚀 go-pugleaf

heathh@cco.caltech.edu (Heath Ian Hunnicutt) writes:

>	From what I understand, that's not totally true.  While the _specs_
>might be the same, IBM also submitted a rationale for the DES method.  This
>rationale document remains classified, and some wonder if it contains
>information that severely weakens DES.

This keeps coming up.  My guess, and it's only a guess, is that this 
document addresses the selection criteria for the key size.  Any
information regarding the S-box design would be deep black,  and
only those directly involved would even know of its existance.
The selection of the key size would involve assesment of future
computer development and might include some information derived
from intelligence services and is most likely what is in this
document.

Regarding the strength of DES, my guess is that given the restrictions
on key size and algorithm complexity, a stronger system could not be
implemented.  NSA would not have wanted to get caught putting out a
crypto system that would be possible broken in public.  It might
give their opponents hope that they might break the military systems.
Bureaucrats resist public embarressment to the maximum extent possible
up to and including release of classified information.