From: Jim McCoy <mccoy@ccwf.cc.utexas.edu>
Date: Sun, 7 Nov 93 15:08:13 PST
To: an41418@anon.penet.fi
Subject: Re: some newbie DC-net questions
In-Reply-To: <9311062341.AA17127@anon.penet.fi>
Message-ID: <199311072306.AA05258@flubber.cc.utexas.edu>
MIME-Version: 1.0
Content-Type: text


an41418@anon.penet.fi (wonderer) writes:
> 
> How do you implement people seeing their neighbors
> coin, but nobody else seeing it? Does it require
> a secure channel between every adjacent person?

Yes.  There are a couple of methods you could use to perform this.  One is
to burn a ton of random noise into a CD-ROM and mail it to your neighbor.
Another is to use public-key encryption to pass a large chunk of data over
the net (you know who your neighbors are, so it is relatively easy for them
to publish a key along with thier address when the net is forming) or you
could all agree to use the same PRNG and then you just pass seed values to
the person you share data with and let them expand it out as needed (if
bandwidth is limited, for example.)

Either way, if one transmission is compromised you are not necessarily left
visible to an evesdropper; they also need to know the random numbers that
are being compared to the data you exchange...

jim