From: Bill Stewart <stewarts@ix.netcom.com>
Date: Tue, 1 Jul 1997 10:38:48 +0800
To: Lucky Green <shamrock@netcom.com>
Subject: Re: Anonymous browsing (was Re: Getting Back to our Radical Roots)
In-Reply-To: <97Jun25.162334edt.32257@brickwall.ceddec.com>
Message-ID: <3.0.2.32.19970630170619.0075ca98@popd.ix.netcom.com>
MIME-Version: 1.0
Content-Type: text/plain



At 01:57 PM 6/25/97 -0700, Lucky Green <shamrock@netcom.com> wrote:
>Regarding DC nets:
>Modern tree structures only double the bandwidth requirement. DC nets are 
>practical today. I would encourage CP's to work on implementations.

How do you do that?  Arrange the XORs to do x0^x1, x2^x3....,
then (x0^x1)^(x2^x3)... etc., ending up with user 0 doing the last XOR,
and broadcasting or tree-casting the results?  It cuts down on bandwidth
for the average user, but does end up with a few users doing most of the work,
and perhaps there's some security risk in the unbalanced workload.
It's an interesting approach, and I suppose you could do a bit more work
(logn instead of 2) to spread the partial results around so more people
can calculate them directly (e.g. user 0 sends user 2 x0^x1, and sends 
user 1 x2^x3, and if you're still paranoid you can have user 0 also send
user 3 x0^x1, which user 2 and user 3 can compare....)

You've probably got to put more thought into getting the details right,
like collision detection and backoff, but it's still doable.


#			Thanks;  Bill
# Bill Stewart, +1-415-442-2215 stewarts@ix.netcom.com
# You can get PGP outside the US at ftp.ox.ac.uk/pub/crypto/pgp
#   (If this is a mailing list or news, please Cc: me on replies.  Thanks.)