From: nobody@REPLAY.COM (Anonymous)
Date: Wed, 21 Jan 1998 10:08:03 +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: <199801210204.DAA02141@basement.replay.com>
MIME-Version: 1.0
Content-Type: text/plain



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.