Re: NSA leak (fwd)

Rohit Khare (
Mon, 28 Jul 1997 16:46:26 -0400 (EDT)

From: (Ian Goldberg)
Reply-To: (Ian Goldberg)

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

In article <>,
Robert Hayden-0797-EMP-HSE <> wrote:
>Say this on the Fight Censorship list. Just FYI.
>---------- Forwarded message ----------
>Date: 19 Jul 1997 17:56:51 -0000
>From: Secret Squirrel <>
>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
>at a White House press conference concerning current bans on the export
>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
>White House officials, reporters, and a troupe of girl scouts from

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
I just know that at my rates, 7.12 TW for 33 minutes (at about
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

- Ian