Schneier Claims on Multiple Encryption

[Roger Bryner]

On Thu, 7 Jul 1994, Kent Borg wrote:
> Kent's Hypothosis: Superencrypting different algorithms with unrelated
> keys can never weaken non-trivial algorithms.
Well, it could, just posibly, once in the enrtopy of your adverage 
algorithim, but then, as you pointed out, you could just use DES as a 
magic IDEA decoder:-)

You can prove that there is no such interaction if you use two different 
algorithims on two halfs of a one time pad message, even with the SAME key.
 
Roger.