Re: Password entropy

[Paul Russell <prussell () ND EDU>]

On 7/23/2006 16:52, Valdis Kletnieks wrote:
> If we had keyboards and brains and systems that accepted Chinese characters
> that represent words as single characters, an 8-word passphrase would be
> as long and nearly as strong as an 8-character random password.  The reason
> the passphrase has to be longer is because you get much less randomness
> and entropy *per character* in a Latin-charset passphrase...

Much of this discussion seems to have focused on the lack of entropy in
English-language words and phrases. Both suffer from the predictability of
letter sequences. Does entropy increase if the 'word' consists of the first
(or last) letters of a phrase? Does it increase further if non-alphabetic
characters are substituted for letters?

--
Paul Russell, Senior Systems Administrator
OIT Messaging Services Team
University of Notre Dame
prussell () nd edu