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From: wayner@cello.cs.cornell.edu (Peter Wayner)
Newsgroups: comp.org.eff.talk
Subject: DES and the NSA...
Message-ID: <50562@cornell.UUCP>
Date: 10 Jan 91 16:58:51 GMT
Sender: nobody@cornell.UUCP
Organization: Cornell Univ. CS Dept. Ithaca NY
Lines: 23

My Theory:

DES should be unreadable by the Soviets, but if they
or a third-world country should use it, it would be
nice if we could read the text.

But:

1) The Soviets have good mathematicians.
2) The Soviets (and the Third World) lag in computer
technology.

Therefore use a technological barrier. Make the cipher very strong,
( a paper by Biham and Shamir at Crypto 90 suggests that they did 
this), but weak enough so a very expensive (>$5,000,000) massively
parallel machine could barely attack it with brute force. 

The result is that poor, but smart mathematicians won't stumble on 
any trap-doors you've hidden and only the rich nations form a threat.
(Which they did any ways.) 
Peter Wayner   Department of Computer Science Cornell Univ. Ithaca, NY 14850
EMail:wayner@cs.cornell.edu    Office: 607-255-9202 or 255-1008
Home: 116 Oak Ave, Ithaca, NY 14850  Phone: 607-277-6678