Cracking good times (UNCLASSIFIED)

[robert.portvliet at gmail.com (Robert Portvliet)]

Assuming the attacker retrieves the hashes ...at what password
length\strength do rainbow tables become impractical due to size & time to
generate?

Also, at what length\strength do the online rainbow table cracking services
become ineffective?



On Tue, Jun 30, 2009 at 2:00 PM, Craig <reswob10 at gmail.com> wrote:

> Classification:  UNCLASSIFIED
> Caveats: NONE
>
> Thanks!
>
>
> Craig L. Bowser
> CISSP           SANS GSEC (Gold)
> -------------------------------
> Hard work spotlights the character of people; some turn up their sleeves,
> some turn up their noses, and some don't turn up at all!
> -----Original Message-----
> From: pauldotcom-bounces at mail.pauldotcom.com
> [mailto:pauldotcom-bounces at mail.pauldotcom.com] On Behalf Of Dan Stadelman
> Sent: Tuesday, June 30, 2009 1:46 PM
> To: PaulDotCom Security Weekly Mailing List
> Subject: Re: [Pauldotcom] Cracking good times
>
> The equations should say:
>
> > 20^72 * time to *try* one password == a lot of time
>
> but I am sure you get the idea ;)
>
> Dan
>
>
>
> On Tue, Jun 30, 2009 at 11:44 AM, Dan Stadelman<bioradmeister at gmail.com>
> wrote:
> > It is really hard to answer this one because it really "all depends"
> > on a lot of things - mainly how long it would take to test one
> > password.  This can vary with system set up - if the user has access
> > to the password hashes, etc.
> >
> > If you are trying to make up some stats you could do something like
> > this (I assume you know this):
> >
> > 26 + 26 + 10 + 10 = 72 characters
> >
> > arranged 20 ways
> >
> > 20^72 * time to crack one password == a lot of time
> >
> > arranged 15 ways
> >
> > 15^72 * time to crack one password == a bit less time
> >
> > This is assuming there isn't some short cut to figuring out the
> > password - like it is on a sticky note on someones monitor (which
> > probably will happen if you are having such long passwords that are
> > changing frequently).
> >
> > Laters,
> >
> > Dan
> >
> >
> >
> >
> > On Tue, Jun 30, 2009 at 9:39 AM, craig bowser<reswob10 at gmail.com> wrote:
> > > Does anyone know a good reference for listing password cracking
> > > times?  I'm trying to find some stats to determine if we should pick
> > > a 20+ character password for service accounts and only change every 6
> > > or 12 months or pick a shorter password length (10-12 characters) and
> change every 90 days or so.
> > > All passwords would be using all four character sets (Aa1!).
> > >
> > >
> > >
> > > Thanks.
> > >
> > >
> > >
> > >
> > >
> > > Craig L. Bowser
> > >
> > > CISSP       SANS GSEC (Gold)
> > >
> > > -------------------------------
> > >
> > > Nothing makes a person more productive than the last minute. -
> > > Contributed by Jeff Pappas
> > >
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