Openwall GNU/*/Linux - a small security-enhanced Linux distro for servers
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date: Wed, 25 May 2011 22:18:38 +0200
From: magnum <rawsmooth@...dband.net>
To: john-dev@...ts.openwall.com
Subject: Re: BSDI poor in OMP4/OMP7 when doing real work

On 2011-05-23 15:06, Solar Designer wrote:
> magnum -
>
> On Mon, May 23, 2011 at 02:37:05PM +0200, magnum wrote:
>> Using the OMP4 *or* OMP7 patch on 1.7.7, the BSDI format performs very
>> poorly in real cracking (test suite) even though --test show a good
>> speedup. Actually the reported figure from real cracking is also high
>> but the real time is awful. It does find all 1320 passwords.
>>
>> Plain 1.7.7:
>> --test     77004 c/s
>> testsuite  2 seconds, reported c/s 78586
>>
>> 1.7.7 + OMP4
>> --test     128098 c/s
>> testsuite  1 minute, 11 seconds, reported c/s 123860
>
> I haven't tried this, but my guess is that the problem may be due to the
> increase of *_keys_per_crypt.  When your wordlist has all the correct
> passwords and nothing else, it is quicker not to test multiple candidate
> passwords against each hash (even if partially done in parallel), but
> rather to take each one candidate password and test it alone - then
> remove the cracked hash (and have less work to do from that point on).

You were right, and the same problem could actually be seen in mskrb5 
too. Fixed now. Fine-tuning OMP is very time-consuming, and specific per 
format.

What I don't understand though is why is the reported c/s is so high?

thanks
magnum

Powered by blists - more mailing lists

Your e-mail address:

Powered by Openwall GNU/*/Linux - Powered by OpenVZ