From: iang@cs.berkeley.edu (Ian Goldberg)
Date: Mon, 28 Jul 1997 05:57:10 +0800
To: cypherpunks@cyberpass.net
Subject: Re: NSA leak (fwd)
In-Reply-To: <Pine.SOL.3.95.970719232017.28206B-100000@orion.means.net>
Message-ID: <5rgfra$ro@abraham.cs.berkeley.edu>
MIME-Version: 1.0
Content-Type: text/plain



[To cypherpunks, copied to fight-censorship (which I'm not on).]

In article <Pine.SOL.3.95.970719232017.28206B-100000@orion.means.net>,
Robert Hayden-0797-EMP-HSE  <rhayden@orion.means.net> wrote:
>Say this on the Fight Censorship list.  Just FYI.
>
>---------- Forwarded message ----------
>Date: 19 Jul 1997 17:56:51 -0000
>From: Secret Squirrel <nobody@secret.squirrel.owl.de>
>To: fight-censorship@vorlon.mit.edu
>Subject: NSA leak
>
>WASHINGTON (AP) - In a rare moment of openness bordering on glibness, a
>senior official at the super-secret National Security Agency was overheard
>at a White House press conference concerning current bans on the export of
>encryption technology saying, "It would not take any twelve times the age of
>the universe to decrypt a 128-bit message.  Thirty-three minutes is more
>like it."
>
>Observers at the press conference indicated that the senior official's
>remarks were intended to be overheard by those standing nearby, who included
>White House officials, reporters, and a troupe of girl scouts from Lundane,
>Illinois.

Uh-huh.  Unless the Administration has granted a secret Executive Order
repealing the Laws of Physics for the NSA, the above statement, if true,
would imply one of the following things:

1. The NSA has a reversible computing machine with at least 2^128*128 bits
   = 5.44*10^39 bytes = 4.95*10^27 TB of memory.  Hardly.

2. Their cracker changes the state of 2^128 bits in 33 minutes.  This is
   being extremely generous; it assumes (in the style of Schneier) that
   they only have to increment a counter through each possible key, and
   that _checking_ the key is free.  Let T be the temperature at which
   they run their computer.  Again, be very generous, and assume that
   their computer is in deep space, with an ambient temperature of 
   about 3 Kelvins, and that their super-fast processor does not heat
   up the system, so T = 3K.

   Then their cracker would require 2^128 * k * T of energy in 33 minutes
   (k is Boltmann's constant, 1.38*10^-23 J/K).  This works out to a power
   requirement of 2^128*k*(3K)/(33*60s) = 7.12 TW (terawatts).  This
   seems also unlikely.  (Actually, for all I know, terawatt power sources
   may exist; that's out of my field.  Please let me know if this is the case.
   I just know that at my rates, 7.12 TW for 33 minutes (at about $.10/kWh)
   would cost $392 million each time they wanted to crack a key (half that
   in the average case; and of course, their electrical rates are probably
   lower than mine...).  Again, this is being _extremely_ generous in
   the energy consumption calculations.  Note also that this dollar figure
   depends only on the size of the key and your power rate; the 33 minute
   figure cancels out.)

   There could be some tradeoff in the above two cases.

3. They have a quantum computer, or some alien technology, or something
   else we know pretty much nothing about.

Given this choice, I would vote for #3. :-)  However, I'd go out on a limb
and say that the NSA guy was simply lying (or that the anecdote itself is
mistaken).

   - Ian