Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.2 9/18/84; site utcsrgv.UUCP Path: utzoo!utcsrgv!eas 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 Distribution: ont Organization: CSRI, University of Toronto Lines: 34 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.