I like the idea behind the tool, somewhat, but I don't know how exact it can
be. I think Alexander's reasoning below has some strength behind it. Is it
something like trying to predict when a random number might come up. Keep
rolling an n-faced die for long enough and sometimes your number may come up
near the 'beginning' or near the 'end'. Who can say? Obviously, that all
depends on how the program is actually implemented to brute force. Is it
purely sequentially?
Which also makes me wonder, what is the 'seconds to crack' based on? A
single machine? An array of distributed machines etc?
I think you can give some 'good' idea of how strong the passphrase is but
maybe not as exact as you hope. I could be wrong(and often am).

-----Original Message-----
From: listbounce (at) securityfocus (dot) com [email concealed] [mailto:listbounce (at) securityfocus (dot) com [email concealed]] On
Behalf Of Alexander Klimov
Sent: Wednesday, July 14, 2010 6:54 PM
To: focus-ms (at) securityfocus (dot) com [email concealed]
Subject: Re: TGP Password Strength Checker online

On Tue, 13 Jul 2010, Thor (Hammer of God) wrote:
> However, what IS different is that you can actually get an idea of
> exactly how many iterations it will take to crack both a particular
> password specifically and the keyspace it "lives" in, apply that to
> actual TIME required to crack it. I like that part, and have found
> it to be valuable, so here it is in case you do as well.

An incorrect precise number is worse than no number at all: if
you assure user that it takes 129,052,722,140 iterations to
guess password "password", or 2,322,220,814,264,750,000 to
guess "qwerty123456", it only misleads. The real attackers start
guessing not from "a", but in the most-probable-first order.
What is this order depends on the traits of the mark: the first
password to try, can as well be "password", "qwerty123456", or
"salasana".

--
Regards,
ASK

[ reply ]