[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: a simple explanation of DC-Net
On Mon, 6 Feb 1995, Wei Dai wrote:
> P.S. I realize someone has probably written something like this
> already, but I hope this explanation helps someone who is still
> puzzled.
I've written a test-bed IRC client which uses DC Nets to allow multiple
people to talk on an IRC channel anonymously. It operates in a ring,
with every participant showing his/her random bit stream with the
neighbor to the "left." Participants compare their bit stream with the
one their neighbor shares with them, and broadcasts the differences
(with lies indicating xmitted "1" bite) to all participants. The
difference bits for each round are totalled together modulo 2 by each
participant, and any anonymous broadcasts can be determined from those
totals.
My implementation was a quick project for a class and lacks some really
important features:
1) used built-in PRNG
2) does not encrypt private messages for bit stream sharing between
neighbors
3) no ALOHA or similar protocol for dealing with message collisions
4) ring could be expanded to more complex graph to increase number of
colluding participants needed to break anonymity.
BTW - There have been a few other papers on DC-Nets since Chaum including
detections of DC-Net disrupters, and protection against a group of active
attacks. I include a report with my code now available at
ftp://ftp.csua.berkeley.edu/pub/cypherpunks/applications/dc-irc.alpha.tar.gz
which goes into more details on these matters and has references.
-Thomas