🚀 go-pugleaf

In article <1992Nov19.215029.22401@bernina.ethz.ch>, caronni@nessie.cs.id.ethz.ch (Germano Caronni) writes:
|> You are discussing the act of padding an encrypted text so, that there
|> are no peaks in any statistic whatsoever. How about encrypt the whole text,
|> analyze character-frequencies, and sequences of characters, and then pad
|> the text in predefined places with characters that flatten the peaks or create
|> wrong peaks in some sorts of statsistic you would like to apply ? As long as
|> the opponent does not *know* you have added these pads, perhaps this will
|> work ?
|> Other ideas ?
|> 	
|> 	gec
|> -- 
|> Instruments register only through things they're designed to register.
|> Space still contains infinite unknowns.
|> 
|> Germano Caronni    caronni@nessie.cs.id.ethz.ch

But, in the real world, the opponent will quickly find out.

Consider the press release.  It is sent, in encrypted and padded form
to 100 branch offices of Fortune 500 firm X.  The opponent intercepts
some of these.

A day later, the plain text is published verbatim, freely available.
The opponent counts the bytes and goes "aha".

This sort of thing is not uncommon and would reveal the padding pretty
readily; deciding which text was the press release is a separate problem,
but 100 copies of the same thing is a pretty good clue. . .and this
exact kind of attack _has_ succeeded many times.  Government crypto
groups spend a lot of time on it.  They can often correlate very 
accurately even when the can't solve the cipher.

-- 
   Larry W. Loen        |  My Opinions are decidedly my own, so please
                        |  do not attribute them to my employer