Network Extractor Protocols

We design efficient protocols for processors to extract private randomness over a network with Byzantine faults, when each processor has access to an independent weakly-random n-bit source of sufficient minentropy. We give several such network extractor protocols in both the information theoretic and computational settings. For a computationally unbounded adversary, we construct protocols in both the synchronous and asynchronous settings. These network extractors imply efficient protocols for leader election (synchronous setting only) and Byzantine agreement which tolerate a linear fraction of faults, even when the min-entropy is only 2(log n)Ω(1) . For larger min-entropy, in the synchronous setting the fraction of tolerable faults approaches the bounds in the perfect-randomness case. Our network extractors for a computationally bounded adversary work in the synchronous setting even when 99% of the parties are faulty, assuming trapdoor permutations exist. Further, assuming a stro...

• Type: Conference
• Year: 2008
• Where: FOCS
• Authors: Yael Tauman Kalai, Xin Li, Anup Rao, David Zuckerman
• Keywords: Efficient Protocol, FOCS 2008, Network Extractor, Synchronous Setting, Theoretical Computer Science