Re: What have we done? (Here's what.)

Karl J. Runge (runge@crl.com)
Sat, 21 Jun 1997 12:14:27 -0700


On Sat, 21 Jun 1997, C Matthew Curtin <cmcurtin@research.megasoft.com> wrote:
> number of | time to crack the message
> tumblers | (on the average, at DESCHALL Project speed)
> ----------|-------------
> 40 | 78 seconds
> 48 | 5 hours
> 56 | 59 days
> 64 | 41 years
> 72 | 10,696 years
> 80 | 2,738,199 years
> 88 | 700,978,948 years
> 96 | 179,450,610,898 years
> 128 | 770,734,505,057,572,442,069 years

Let me add my twist to the nice calculation Matt has done.

Here are some estimates with respect to a "Quantum Computer(TM)".

In an atom, an electron can orbit around the nucleus roughly 10^15 times
per second.

If we set the DESCHALL assembly code gurus loose on a quantum computer I'm
positive ;-) they could refine their code to the point where it checks
one key every time an electron does a single orbit.

Since I'm trying to construct an UPPER BOUND here, bear with me and let me
further assume each atom acts as an independent computer.

An estimate to the total number of particles in the Universe is 10^80
(a great ice-breaking fact to blurt out at parties!)

So... the Ultimate Code Breaking computer would be every atom in the Universe
trying a key each electron orbit. (I gotta get me one of those!)

How many keys could it check in, say, 10 billion years (the estimated
age of the universe), which is about 10^10 * 10^7 = 10^17 seconds?

Number of keys = (number of computers)
* (keys per second for one computer)
* (number of seconds)

Number of keys = 10^80
* 10^15
* 10^17

= 10^112 = 2^372

So a 372 bit key is REALLY safe IMHO against brute force attack!

This is basically just doing Triple-DES twice, which I imagine
is barely noticeable performance-wise when encrypting/decrypting
messages.


Karl