[1088] in cryptography@c2.net mail archive
Re: Thoughts on the next target.
daemon@ATHENA.MIT.EDU (David P. Jablon)
Wed Jun 25 12:10:38 1997
Date: Wed, 25 Jun 1997 09:44:50 -0400
To: "Marcus Leech" <mleech@nortel.ca>
From: "David P. Jablon" <dpj@world.std.com>
Cc: cryptography@c2.net
In-Reply-To: <199706242032.AA048404375@bftzh114.ott.bnr.ca>
Marcus,
To continue our debate over "newsworthy" targets ...
You wrote:
>Yup, but it [targeting a widely-used challenge/response password method]
> isn't something that's going to require a massively-parallel
> brute-force attack, only a few-suitably motivated people--either
> through session-hijacking (which is cryptographically uninteresting),
> or a dictionary/"password cracking" attack against a single user.
>
>If we assume that the input key is eight characters consisting
> entirely of lowercase alphabetics, and we can test 35000/second on a
> "normal" machine, then the password is cracked in about a month on a single
> system.
Why assume? A massively parallel eavesdropper attack should
work against many apparently "good" passwords, when using a "bad"
method. Maybe this is obvious to readers of cryptography@c2.net
but then again, I'm sure we all knew that DES-56 was
brute-forceable for the right price.
> This tells us nothing that we don't already know: picking bad passwords
> weakens your system. [ Surely, not "my" system? :-) ]
On the contrary, picking bad systems weakens your password.
A "bad" password for one system can be just fine for another.
Perhaps an eavesdropper crack of "2Jj3$dld" or a short pass-
phrase in a challenge/response system would be newsworthy to
some people. It may also be surprising to some that "rover"
survives eavesdropper attack in a stronger system.
------------------------------------
David. Jablon
web: http://world.std.com/~dpj/
email: dpj@world.std.com
