Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.2 9/18/84; site oberon.UUCP Path: utzoo!watmath!clyde!bonnie!akgua!whuxlm!harpo!decvax!ittvax!dcdwest!sdcsvax!sdcrdcf!uscvax!oberon!tli From: tli@oberon.UUCP (Tony Li) Newsgroups: net.crypt Subject: Re: Encryption using compression Message-ID: <78@oberon.UUCP> Date: Tue, 9-Jul-85 03:47:40 EDT Article-I.D.: oberon.78 Posted: Tue Jul 9 03:47:40 1985 Date-Received: Mon, 15-Jul-85 06:51:16 EDT References: <5992@duke.UUCP> <11379@brl-tgr.ARPA> <5993@duke.UUCP> Reply-To: tli@oberon.UUCP (Tony Li) Distribution: net Organization: U. of So. Calif., Los Angeles Lines: 19 Summary: The problem with your beautiful theory is that you haven't changed the frequency of the characters in your text. By running compress on the plaintext, you've simply inserted a substitution cipher before your shuffle cipher. Once the natural language of the plaintext becomes known, it should quickly become obvious to the cryptographer that your character frequencies are incorrect. This leads immediately to the idea of a substitution. May I suggest Gaines as an excellent place to begin your reading? Even the introductory chapters and a pocket calculator are useful for simple cryptograms. Cheers, Tony ;-) -- Tony Li ;-) Usc Computer Science Uucp: ...!{{decvax,ucbvax}!sdcsvax,hplabs,allegra,trwrb}!sdcrdcf!uscvax!tli Bitnet: tli@uscvaxq, tli@jaxom, tli@ramoth Csnet: tli@usc-cse.csnet Arpa: tli@usc-ecl.arpa