[1112] in cryptography@c2.net mail archive
Re: cracking n-DES?
daemon@ATHENA.MIT.EDU (Perry E. Metzger)
Sat Jun 28 02:23:00 1997
To: "Scott Baker" <sbaker@ohcu.org>
cc: cryptography@c2.net
In-reply-to: Your message of "Sat, 28 Jun 1997 01:04:22 CDT."
<862564C4.00213238.00@ohcu.org>
Reply-To: perry@piermont.com
Date: Sat, 28 Jun 1997 02:18:27 -0400
From: "Perry E. Metzger" <perry@piermont.com>
"Scott Baker" writes:
> daw@cs.berkeley.edu wrote:
> >Ok, challenge taken. If I understand the proposal correctly, d|t|d|t|d
> >isn't nearly as strong as 3-DES: this post describes how to break it with
> >3 * 2^^{56} trial decryptions and one chosen plaintext query, I think.
>
> So, then, how long would this take on, say, a Pentium 133?
I have no idea, but it will probably take a factor of 2^56 less time
(thats a factor of 72057594037927936) than straight 3DES would take to
crack if Dave is right -- in other words, it is far, far, far, far
less strong than it should be given the key size. I have to study
Dave's attack more, but its quite a real difference in power.
Perry
