Re: Password entropy

[Robert Kerr <r.kerr () CRANFIELD AC UK>]

On Sun, 2006-07-23 at 16:52 -0400, Valdis Kletnieks wrote:

> A bit of thought will reveal a lot of other 2 and 3 character combinations
> that are a lot more common ('ing', etc...).  The end result is that running
> English text averages about 2.5 to 3 bits of entropy per character, and
> even skript kiddie 'l33t sp33k' and that obfuscated spam stuff is probably
> still under 4 bits/character (I'll go out on a limb and hypothesis that
> if it's trying to pass itself off as English, and has over 3.5 bits/char
> of entropy, it's been too obfuscated to be easily readable....)

A quite interesting demonstation of this concept can be found online:

http://math.ucsd.edu/~crypto/java/ENTROPY/

It's surprising to see how many letter you can guess first time.

--
 Robert Kerr