Entropy Estimations for die and pass phrases

Newsgroups	sci.crypt
Subject	Entropy Estimations for die and pass phrases
From	"David Eather" <eather@tpg.com.au>
Message-ID	<op.x6oirrzqwei6gd@phenom-pc> (permalink)
Date	2015-10-18 12:05 +1000

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Just a short table of entropy estimates (Shannon entropy for the purest  
hair splitters)

6 sided dice 2.58 bits per throw
8 sided dice 3.99 bits per throw
10 dided dice 3.32 bits per throw
Letters from a Scrabble set 4.32 bits per tile (this is higher because the  
distribution of letters is a little more even than in natural language  
because some letter must have one tile even though they represent less  
than 1% of language)

Making a password from the first letter of every word in a pass-phrase  
yield about 3.9 - 4.0 bits per letter.

However, Professor Unruh has mentioned his experiments with all lower case  
words taken from his texts which yielded 4.1 bits per word. This accords  
very well with the Scrabble result and leads me to conclude that although  
the difference is relatively small there is no reason to use mixed cases  
when and only when) making a pass phrase from the first letter of words in  
a sentence.

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Entropy Estimations for die and pass phrases  "David Eather" <eather@tpg.com.au> - 2015-10-18 12:05 +1000
  Re: Entropy Estimations for die and pass phrases Robert Wessel <robertwessel2@yahoo.com> - 2015-10-18 00:14 -0500
    Re: Entropy Estimations for die and pass phrases "David Eather" <eather@tpg.com.au> - 2015-10-18 16:40 +1000
  Re: Entropy Estimations for die and pass phrases  "David Eather" <eather@tpg.com.au> - 2015-10-18 16:41 +1000
  Re: Entropy Estimations for die and pass phrases Karl-Uwe Frank <karl.frank@freecx.co.uk> - 2015-10-18 23:22 +0200
    Re: Entropy Estimations for die and pass phrases Paulo Marques <pmarques@grupopie.com> - 2015-10-19 15:24 +0100
  Re: Entropy Estimations for die and pass phrases Jeffrey Goldberg <nobody@goldmark.org> - 2015-10-19 00:17 -0500
    Re: Entropy Estimations for die and pass phrases rpw3@rpw3.org (Rob Warnock) - 2015-10-19 12:00 +0000
      Re: Entropy Estimations for die and pass phrases Jeffrey Goldberg <nobody@goldmark.org> - 2015-10-19 14:52 -0500
        Re: Entropy Estimations for die and pass phrases David Malone <dwmalone@walton.maths.tcd.ie> - 2015-10-20 08:00 +0000
          Re: Entropy Estimations for die and pass phrases Jeffrey Goldberg <nobody@goldmark.org> - 2015-10-20 12:32 -0500

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