From: tcmay@netcom.com (Timothy C. May)
Date: Mon, 6 Feb 95 22:22:38 PST
To: weidai@eskimo.com
Subject: Re: a simple explanation of DC-Net
In-Reply-To: <199502070122.AA01568@mail.eskimo.com>
Message-ID: <199502070620.WAA29156@netcom4.netcom.com>
MIME-Version: 1.0
Content-Type: text/plain


Wei Dai wrote:

> The DC-Net is not very easy to understand.  I'll try to explain the most
> important parts of the concept as simply as I can.
...nice explanation elided...

> P.S.  I realize someone has probably written something like this
> already, but I hope this explanation helps someone who is still
> puzzled.  If nothing else, it serves as a sanity check on my own
> understanding.

Yes, I wrote up a similar explanation for the Extropians list, in
mid-1992, before our list existed. (It's been redistributed here a
couple of times, and is in some of the CP archives an/or URLs reported
here.)

Eric Hughes and I did a anthropomorphic demo of DC-Nets a couple of
years ago, at the first CP meeting. That is, we got up in front of
folks and literally acted-out a simple transmission (and even this
took some minutes, to make clear the protocols, etc.).

My estimate is that the averagely bright Cypherpunk (which is to say,
_very_ bright person) can get the key ideas of DC-Nets in a few hours
of careful thinking and diagramming of the ideas in the paper, which
is of course archived at the Cypherpunks site (and probably readily
accessible in several URLs). By "key ideas" I mean the first 3-4
pages of the paper, whjere the ideas are laid out.

Issues of collusion and disruption are what Chaum spends most of his
1988 paper on, and start after the first introductory pages. Sub-nets,
to reduce collusion, for example. Later papers, such as those by the
Pfitzmanns and by Jurgen Bos, deal in much more detail with
disruption.

(By the way, I mentioned to Chaum, in Monte Carlo last week, our
continuing fascination with DC-Nets, despite the difficulties in fully
implementing/using them. Chaum was aware of the efforts by the Austin
group, and was pleased to hear that several parallel are continuing. I
got the impression that we are the only people in the world still
looking at this stuff, which is not as bad as it sounds. You see,
those writing papers have moved on to other things, whereas
Cypherpunks is a list devoted to practical implementations and
demonstrations, and few others are, so we have a continuing interest.
Chaum was very complimentary about the Cypherpunks.)

--Tim May

-- 
..........................................................................
Timothy C. May         | Crypto Anarchy: encryption, digital money,  
tcmay@netcom.com       | anonymous networks, digital pseudonyms, zero
                       | knowledge, reputations, information markets, 
W.A.S.T.E.: Aptos, CA  | black markets, collapse of governments.
Higher Power: 2^859433 | Public Key: PGP and MailSafe available.
Cypherpunks list: majordomo@toad.com with body message of only: 
subscribe cypherpunks. FAQ available at ftp.netcom.com in pub/tc/tcmay