Article View: sci.crypt
Article #3371Re: bitwise exclusive-or
From: falk
Date: Fri, 30 Jan 1987 17:33
Date: Fri, 30 Jan 1987 17:33
19 lines
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1679 bytes
In article <875@mecc.MECC.COM> sewilco@mecc.UUCP (Scot E. Wilcoxon) writes: >It is very easy for an exclusive-or to fail. Too many zeroes and plain >text is the result. Too many ones and it is inverted plain text. So what? All you get is small fragments of recognizable text. For all the spy who sees it knows, it could have been something else that got changed *into* something readable. If your random number is any good at all, very long strings of zeros and ones won't appear. For instance, for twenty characters in a row to come out unencrypted (assuming you're using 7-bit ascii) would require 140 zeros in a row to come out of the random number generator. This happens once every 199,113,796,415,000,000,000,000,000,000,000,000,000,000 characters of output. Note that the phrase "Nuke Moskow tomorrow", complete with correct spelling and capitalization occurs in encrypted text (regardless of what the original text said) with *exactly* the same frequency as a 20-character burst of unencrypted text. -ed falk, sun microsystems (don't need no nsa lineater for this one)
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Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: arc1-ca.pugleaf.net!utzoo!watmath!clyde!rutgers!sri-spam!ames!oliveb!sun!peregrine!falk From: falk@peregrine.UUCP Newsgroups: sci.crypt Subject: Re: bitwise exclusive-or Message-ID: <12419@sun.uucp> Date: Fri, 30-Jan-87 12:33:32 EST Article-I.D.: sun.12419 Posted: Fri Jan 30 12:33:32 1987 Date-Received: Sat, 31-Jan-87 08:20:45 EST References: <434@ethz.UUCP> <5580@brl-smoke.ARPA> <875@mecc.MECC.COM> Sender: news@sun.uucp Reply-To: falk@sun.UUCP (Ed Falk) Organization: Sun Microsystems, Mountain View Lines: 19