From: pmetzger@shearson.com (Perry E. Metzger)
Date: Mon, 19 Oct 92 17:08:26 PDT
To: hkhenson@cup.portal.com
Subject: one time pads.
In-Reply-To: <9210190136.1.13588@cup.portal.com>
Message-ID: <9210191948.AA13028@newsu.shearson.com>
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>From: hkhenson@cup.portal.com

>I can suggest a way to "distribute" a one time pad, even though the 
>people never meet.  Just agree over the phone on which CD ROM to use,
>and some forumula for an offset into the CD ROM.  You might want to
>throw away some of the data to make the bit stream less regular, but
>with 600 meg, who cares?  Keith Henson

This seems equivalent to the old "dictionary" or "book" cyphers that
people sometimes used. Good cryptanalysts broke them routinely. I'll
leave it to your imagination how one might do it, but I'll just note
that if you picked a few arbitrary bytes, say bytes 30-40, of all the
CDs in the record store, you would find that those few bytes likely
distinguish all but prehaps a token number of CDs.

Perry