Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.1 (Tek) 9/26/83; site azure.UUCP Path: utzoo!watmath!clyde!floyd!vax135!cornell!uw-beaver!tektronix!azure!billp From: billp@azure.UUCP (Bill Pfeifer) Newsgroups: net.crypt Subject: Re: One-time pads Message-ID: <2540@azure.UUCP> Date: Fri, 17-Feb-84 12:48:27 EST Article-I.D.: azure.2540 Posted: Fri Feb 17 12:48:27 1984 Date-Received: Sun, 19-Feb-84 08:08:20 EST Organization: Tektronix, Beaverton OR Lines: 18 Gene Spafford writes: >> A difficulty is that in any truly random bit string, there is very >> possibly a run of M zeros, with M up to the size of the message. That >> is, it is expected that at some time there will be a long enough run of >> zeros so as to not encrypt a major portion of the text. In fact, it is >> entirely possible that a random key could be all zeros, thus producing >> an encrypted text equal to the plain text! That is true. However, we must look at the probabilities. There is a chance that a string of zeroes leaves a portion of the text unencrypted. There is an *equal* chance that a certain combination of random digits produces cleartext of opposite meaning, or text from a future OSHA regulation, or a portion of a german poem. In other words, if you find something readable, in whatever language, in a message that has been encrypted with a one-time-pad of *truly* random digits, it is equally meaningful as "skpebcvus;fjwuy*z". Bill Pfeifer {cbosgd,decvax,harpo,ihnss,ogcvax,pur-ee,ucbvax,zehntel} !tektronix!tekmdp!billp