From: David Neal <dneal@usis.com>
Date: Thu, 17 Aug 95 12:35:56 PDT
To: "Rev. Mark Grant" <mark@unicorn.com>
Subject: Re: First known purchase of physical goods with cyberbucks
In-Reply-To: <Pine.3.89.9508171704.A1363-0100000@unicorn.com>
Message-ID: <Pine.BSI.3.91.950817135759.5199C-100000@usis.com>
MIME-Version: 1.0
Content-Type: text/plain


On Thu, 17 Aug 1995, Rev. Mark Grant wrote:

> 
> [Feel free to forward to anywhere you feel is appropriate]
> 
> -----BEGIN PGP SIGNED MESSAGE-----
> 
> 
> For some time now, Adam Back has been offering to sell RSA T-shirts for
> cyberbucks (DigiCash's experimental anonymous digital cash system), but
> no-one has had enough available to take him up on it. However, thanks to
> the success of the ecm mailing list (ecm@ai.mit.edu) and WWW site
> (http://www.c2.org/~mark/ecash/ecash.html), today I finally managed to 
> collect enough c$ to buy one.

I just had a wicked thought. What happens when people combine challenge key
cracking with e-cash?

Lesse -- 2^40 keys = 1,099,511,627,776 keys.  Damien was able to get
850000-1.3 million keys per second.  Let's go for the low-end and
use 8000 keys per second which is in the range of his sparcstations
(a very common machine on the internet).  We "only" need 38,178
machines to crack the key in 8 hours.   Each of those workstations
is going to test 28,800,000 keys and we'll assign a nominal value of
$1,000 to cracking the key.  (Most people have $1k of room on their
visa or m/c, no?)  Splitting the booty 50/50 gives someone $500 
or about 1.79 e-cents per 100k keys tested. 

So, could 38,000 people be enticed into running a sparc-cycle
cracking daemon for a 1 in 38,000 chance at $500?  :-)