From: William Knowles <erehwon@c2.org>
Date: Sat, 22 Jun 1996 06:03:47 +0800
To: jim bell <jimbell@pacifier.com>
Subject: Re: Federal Key Registration Agency
In-Reply-To: <199606210601.XAA03610@mail.pacifier.com>
Message-ID: <Pine.SUN.3.91.960621030154.14703C-100000@infinity.c2.org>
MIME-Version: 1.0
Content-Type: text/plain


On Thu, 20 Jun 1996, jim bell wrote:

> At 09:20 PM 6/20/96 -0400, Michael Froomkin wrote:
> >I have seen the text of the speech.  The wire service accounts wildly,
> >wildly exaggerate.  This is a non-story...except for AG Reno's assertion
> >that it would take the government a year to break one DES message with a
> >"supercomputer".  She presumably believes this.  We know the number for
> >known plaintext attacks, but assuming you don't have a known plaintext,
> >what's a more reasonable assumption? 
> 
> If done in parallel, on a dedicated, 200 MHz custom chip, my WAG says that 
> such a chip could try, and statistically analyze the results of 10 million 
> DES codes per second.   (it would do the decrypts on a number of parallel 
> DES blocks, and look for typical ASCII code pattern probabilities, again all 
> in parallel.)  A typical cracking system might have 100 boards of 100 such 
> chips, or perhaps a 100 billion such decrypts per second.  Checking the 
> keyspace would require 2**19 seconds, or about a half million seconds, or 6 
> days.  Average decrypt, of course, in 3 days.


For a guy that used to be in my killfile, I agree with Jim on this one.


William Knowles
erehwon@c2.org
Finger for public key



--