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From: eas@utcsrgv.UUCP (Ann Struthers)
Newsgroups: ont.events
Subject: Theoretical Aspects Sem./"Constructive & Provably Fair Coin Flips..."
Message-ID: <685@utcsrgv.UUCP>
Date: Mon, 21-Jan-85 14:31:02 EST
Article-I.D.: utcsrgv.685
Posted: Mon Jan 21 14:31:02 1985
Date-Received: Mon, 21-Jan-85 14:46:30 EST
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Organization: CSRI, University of Toronto
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		      THEORETICAL ASPECTS SEMINAR

		      Thursday, Janurary 31, 1985

		          4:00 P.M. SF 1105


		      Professor Shafi Goldwasser
		                M.I.T.
		      Lab. For Computer Science

     "Constructive and Provably Fair Coin Flips in Byzantine Networks"


Abstract:

We present a constructive cryptographic protocol for flippling a fair coin
in unreliable distributed environment under the assumption that a trapdoor
function exists. Our solution is the first one to exhibit a rigorours proof
of correctness.

Randomization is both a powerful tool for efficient computation, and the
best weapon against adversaries. Thus, coin flipping is a fundamental 
primitive for designing protocols in an unreliable network. Our solution
has been used by Bracha to achieve Byzantine agreement in a synchronous
of size n in expected logn time, and in an asynchronous network in polylogn
time.

This is joint with Baruch Awerbuch, Benny Chor and Silvio Micali.