Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.2 9/18/84; site brl-tgr.ARPA Path: utzoo!watmath!clyde!burl!ulysses!mhuxr!mhuxt!houxm!mtuxo!mtunh!mtung!mtunf!ariel!vax135!cornell!uw-beaver!tektronix!hplabs!pesnta!greipa!decwrl!decvax!genrad!panda!talcott!harvard!seismo!brl-tgr!gwyn 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 References: <5992@duke.UUCP> <11379@brl-tgr.ARPA> <5993@duke.UUCP> Distribution: net Organization: Ballistic Research Lab Lines: 11 > ... 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.