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Date: Tue, 19 Jun 2012 09:50:44 +0200
From: Tavis Ormandy <>
Subject: Re: Re: [patch] optional new raw sha1 implemetation

On Tue, Jun 19, 2012 at 09:48:06AM +0200, Tavis Ormandy wrote:
> On Sun, Jun 17, 2012 at 04:45:59PM +0200, Tavis Ormandy wrote:
> > On Sun, Jun 17, 2012 at 04:24:43PM +0200, magnum wrote:
> > > Nice, you boosted it by 13% on my core2 laptop.
> > 
> > Great news! I'll experiment with a few other ideas.
> > 
> I noticed that one of the problems with setting it too high was that
> John calls cmp_one for every hash after a successful cmp_all. cmp_one
> really hurts, so if max_keys_per_crypt is too high, I lose some of the
> benefit to the overhead when there is a partial match.
> I noticed an easy way to fix it is just to check if get_hash() ==
> binary_hash() first, I sent you a pull request to add that. But would
> that work in general for all the other hashes?
> It might matter in the cases where you have high max_keys_per_crypt, and
> very fast hashes. I didn't check if anyone else is doing that, but maybe
> they will in future :-)
> Tavis.

Well, I guess a better solution would be to do a binary search in john
to figure out where the match is to within a min_keys_per_crypt range.
But I don't think it's hot enough to make it worth it... I dont know.


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