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From: gwyn@brl-vgr.ARPA (Doug Gwyn )
Newsgroups: net.lang.c
Subject: Re: Cbenson's data encryption technique (plea for help)
Message-ID: <2347@brl-vgr.ARPA>
Date: Wed, 23-May-84 13:17:08 EDT
Article-I.D.: brl-vgr.2347
Posted: Wed May 23 13:17:08 1984
Date-Received: Thu, 31-May-84 19:22:15 EDT
References: <528@reed.UUCP>
Organization: Ballistics Research Lab
Lines: 4

Look for references to "unicity distance" in the cryptography
literature.  I am not sure how much knowledge of this is in the
public domain so I am reluctant to discuss it, but it is the
answer to your question about appropriate key length.