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From: gwyn@brl-tgr.ARPA (Doug Gwyn )
Newsgroups: net.crypt
Subject: Re: Encryption using compression
Message-ID: <11390@brl-tgr.ARPA>
Date: Sat, 6-Jul-85 21:22:59 EDT
Article-I.D.: brl-tgr.11390
Posted: Sat Jul  6 21:22:59 1985
Date-Received: Fri, 12-Jul-85 03:21:16 EDT
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Organization: Ballistic Research Lab
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> ... I realize I haven't addressed the
> key distribution problem, but then if I meet my friend *once*, then I
> can include a shuffle definition and substitution in the plaintext,
> and the friend will know to use them to decrypt the *next* message.

No, no!  Once the "bad guy" breaks ANY message, all subsequent ones
would come unraveled like a chain stitch.

Key distribution really is a major problem in data cryptosystems.
The simpler the enciphering algorithm, the more key that has to
be supplied to maintain reasonable security.