Follow @Openwall on Twitter for new release announcements and other news
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date: Wed, 16 Nov 2005 10:26:17 +0100
From: Michael Behrisch <>
Subject: Re: Speed up John

Am Mittwoch, 16. November 2005 10:09 schrieb Solar Designer:
> On Wed, Nov 16, 2005 at 09:54:42AM +0100, Michael Behrisch wrote:
> > Am Dienstag, 15. November 2005 21:49 schrieb Solar Designer:
> > >
> > >
> > > Basically, this suffers from the same problem that dJohn and most other
> > > similar hacks do.  Unlike John the Ripper itself, these programs or
> > > John patches would not try candidate passwords in an optimal order.  As
> > > a result, John running on a single CPU for one day might crack more
> > > real-world password hashes than dJohn or JohnNet running on 10 CPUs
> > > would.
> >
> > I don't know anything about the way those tools generate their
> > (packages of) candidate passwords,
> > but if they use john --stdout to generate them, your objections
> > would not apply, would they?
> You're correct.  None of these John hacks I've seen use "john --stdout".
> "john --stdout" would require more bandwidth and would not scale too
> well, though, -- but it's fine for the slower hashes and for not too
> many nodes.

No, my idea was to use john --stdout on the client side. The setup would be 
as follows. The client connects to the server and says "ready to crack".
The server says OK, please take password 1000 to 2000, the client runs
john --stdout, throws away the first 1000 and feeds the next 1000 into
john --stdin and then responds OK to the server which gives the next 
share and so forth. The server needs to know nothing about john, it just gives
the numbers which is very low bandwidth. This would also scale easily.

Michael Behrisch (Tel. +49 30 2093-3123)
HU Berlin, Institut fuer Informatik, Arbeitsgruppe Algorithmen

Content of type "application/pgp-signature" skipped

Powered by blists - more mailing lists

Confused about mailing lists and their use? Read about mailing lists on Wikipedia and check out these guidelines on proper formatting of your messages.