Re: randomdev entropy gathering is really weak

[Jeroen C. van Gelderen]

Kris Kennaway wrote:
> 
> On Sat, 22 Jul 2000, Mark Murray wrote:
> 
> > Lots of references: Schneier's "Applied Cryptography" talks about
> > using Good Hashes for crypto and Good Crypto for hashes. Schneier's
> > site at www.counterpane.com will give you plenty.
> 
> I havent been able to get my hands on Applied Cryptography, but I don't
> recall seeing anything like this on the website. I'll check again.
> 
> > The differnce with the old system and Yarrow is yarrow's self-recovery
> > property; Yarrow screens its internal state from the ouside world
> > very heavily, and provides enough perturbation of it from its
> > copious :-) entropy harvesting to keep the state safe from compromise.
> 
> Yeah, I know all this and agree that Yarrow makes a better /dev/urandom,
> but it doesn't change the fact that Yarrow-256 is only good for 256 bits
> of entropy between reseeding operations. You can pull all you want out of
> it but will never get more than 256 bits until it reseeds.

You don't care in practice, 256 bits are unguessable.
If you do care, you load a different random module :-)

Cheers,
Jeroen
-- 
Jeroen C. van Gelderen          o      _     _         _
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