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To: Ricardo Nabinger Sanchez <rnsanchez@wait4.org>
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Cc: markm@FreeBSD.org, freebsd-arch@freebsd.org
Subject: Re: PRNG on FreeBSD
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On Wed, 4 Oct 2006, Ricardo Nabinger Sanchez wrote:

> Snooping around Wikipedia, I got curious about if it'd worth the effort 
> going from Yarrow [1] to Fortuna [2] algorithm, as the authors (seems to) 
> claim that the latter is better/more secure.
>
> As someone (me) who knows very little on how to effectively compromise a 
> PRNG, what are the tradeoffs?  Yarrow is simpler/faster than Fortuna?

Yarrow is an older PRNG algorithm, and Fortuna is (as I understand it) 
generally considered its successor.  Mark Murray (CC'd), who implemented our 
current /dev/random and Yarrow code, has been working on a Fortuna 
implementation for FreeBSD.

Robert N M Watson
Computer Laboratory
University of Cambridge