From: Kent Crispin <kent@songbird.com>
Date: Thu, 22 Jan 1998 01:28:52 +0800
To: cypherpunks@ssz.com
Subject: Re: (eternity) Eternity as a secure filesystem/backup medium
In-Reply-To: <3.0.5.32.19980117194905.008024e0@pobox1.stanford.edu>
Message-ID: <19980121092011.14981@songbird.com>
MIME-Version: 1.0
Content-Type: text/plain



On Wed, Jan 21, 1998 at 03:04:07AM +0100, Anonymous wrote:
> Bill Stewart writes:
> 
> > >Do the math, though, for 128bit.  There are traditional analyses
> > >which include the amount of silicon on the earth, the number of atoms
> > >in the universe, etc.  The general consensus is that traditional
> > >techniques are not feasible for brute forcing 128bit ciphers before
> > >the heat death of the universe.
> > 
> > Hard to say.  Assuming that Quantum Cryptography doesn't allow
> > finite-sized computers to do large exponentially complex calculations
> > in short finite time, you're probably limited by the number of atoms
> > in the available supply of planets, and Heisenberg may still get you
> > if that's not a low enough limit.  Moore's law isn't forever.
> 
> A practical 128-bit key-cracker could be built with about 10000 cubic
    ^^^^^^^^^
> meters of silicon.  (Figure one transistor per cubic micron, 1 ghz
> operation, do the math...)  The technology to build a computer of that
> size is still a few years away, but it is theoretically possible to build
                                            ^^^^^^^^^^^^^
> a 128-bit key-cracker without using quantum computers or travelling to
> other planets.

"In theory, theory and practice are the same, but in practice they 
are different."

-- 
Kent Crispin, PAB Chair			"No reason to get excited",
kent@songbird.com			the thief he kindly spoke...
PGP fingerprint:   B1 8B 72 ED 55 21 5E 44  61 F4 58 0F 72 10 65 55
http://songbird.com/kent/pgp_key.html