1992-10-24 - entropy measures
Header Data
From: Eric Hughes <hughes@soda.berkeley.edu>
To: cypherpunks@toad.com
Message Hash: 3c38d48ebe6788447fca198f92d44a9ffa68121b79032804da9a7944dc97d602
Message ID: <9210240620.AA08036@soda.berkeley.edu>
Reply To: <9210231641.AA11868@xanadu.xanadu.com>
UTC Datetime: 1992-10-24 06:20:44 UTC
Raw Date: Fri, 23 Oct 92 23:20:44 PDT
Raw message
From: Eric Hughes <hughes@soda.berkeley.edu>
Date: Fri, 23 Oct 92 23:20:44 PDT
To: cypherpunks@toad.com
Subject: entropy measures
In-Reply-To: <9210231641.AA11868@xanadu.xanadu.com>
Message-ID: <9210240620.AA08036@soda.berkeley.edu>
MIME-Version: 1.0
Content-Type: text/plain
Dean:
>Where does uuencoded [compressed] binary lie? I would suspect it lies
>right around where encrypted text is.
Right.
>Presumably straight encrypted
>text is statistically random [7..8], but that when you encrypt to
>just the ascii subset is when you lose the entropy.
Exactly.
uuencoding will have a slightly lower single-character entropy than
the ASCII armor PGP uses because just about every line begins with the
letter 'M'. This will skew the distribution slightly. But a better
way of distinguishing uuencoding and ascii armor is to see that in
falls in the same entropy class, and then just looking at the
alphabetic subsets used.
Eric
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- 1992-10-24 (Fri, 23 Oct 92 23:20:44 PDT) - entropy measures - Eric Hughes <hughes@soda.berkeley.edu>
- 1992-10-26 (Sun, 25 Oct 92 21:41:19 PPE) - Re: entropy measures - Eric Hollander <hh@soda.berkeley.edu>
- 1992-10-24 (Fri, 23 Oct 92 23:20:44 PDT) - entropy measures - Eric Hughes <hughes@soda.berkeley.edu>
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- 1992-10-26 (Mon, 26 Oct 92 08:55:04 PPE) - entropy - Eric Hughes <hughes@soda.berkeley.edu>
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- 1992-10-23 (Thu, 22 Oct 92 23:02:09 PDT) - BBS E-mail policy - Eric Hughes <hughes@soda.berkeley.edu>