Quoting Janus Dam Nielsen j...@cs.au.dk:
In the simple case I want to shout out a number to everybody, even
somebody who is eavesdropping.
But secrecy of what you shout is not the real problem. The problem is
to make sure everyone agrees on what was said. This is not obvious in
the case where people may not follow the protocol. For instance, if
you want a solution that does not depend on computational assumptions,
then if a third or more of the players are corrupt, then there is NO
solution.
Think of 3 players A,B and C, where A wants to broadcast a message,
say 0 or 1. One player may be corrupt. So A is supposed to send a bit
b to both B and C. Say B hears 0 from A. He doesn't know if A said the
same to C. He can ask C what he heard, but if C says A said 1 to me,
there is no way to tell if A or C is lying..
regards, Ivan
--
Janus
Den 10/03/2009 kl. 12.23 skrev Ivan Bjerre Damgård:
It can definitely be useful to have a broadcast method, for
instance to complete the implementation of the asynchronous
maliciously secure protocol, we will need broadcast.
But one needs to be careful about what kind of security we want.
There is a whole jungle of protocols, depending on whether it is
unconditional or computational security, synchronous or
asynchronous network, and what number of players you assume can be
corrupt. I think a protocol of Bracha has in fact already been
implemented in VIFF
regards, Ivan
Quoting Janus Dam Nielsen trac...@viff.dk:
New submission from Janus Dam Nielsen janus.niel...@alexandra.dk:
I would like to see a broadcast method in the Runtime class. The
purpose of the broadcast method should be to distribute a public value
among all parties (or some subset of parties).
A case: All parties in a computation needs to read a value from
standard in, and it is a different value for each party. We want to
tell the value to everybody else.
An example use could be like the input method:
a,b,c = runtime.broadcast([1,2,3], value)
Similarly, broadcast can be used in a conditional if only some subset
of parties wants to distribute a value.
--
assignedto: mg
messages: 310
nosy: jdn, mas, mg
status: chatting
title: Broadcast
type: wish
VIFF Issue Tracker trac...@viff.dk
http://tracker.viff.dk/issue80
___
viff-devel mailing list (http://viff.dk/)
viff-devel@viff.dk
http://lists.viff.dk/listinfo.cgi/viff-devel-viff.dk
___
viff-devel mailing list (http://viff.dk/)
viff-devel@viff.dk
http://lists.viff.dk/listinfo.cgi/viff-devel-viff.dk
___
viff-devel mailing list (http://viff.dk/)
viff-devel@viff.dk
http://lists.viff.dk/listinfo.cgi/viff-devel-viff.dk
___
viff-devel mailing list (http://viff.dk/)
viff-devel@viff.dk
http://lists.viff.dk/listinfo.cgi/viff-devel-viff.dk
