{"id":{"repo_id":"mit","oai_identifier":"oai:dspace.mit.edu:1721.1/121665"},"canonical_url":"https://search.dev.ndltd.org/etd/mit/oai:dspace.mit.edu:1721.1/121665","repository":{"repo_id":"mit","name":"MIT","base_url":"https://dspace.mit.edu/oai/request"},"display":{"title":"Synchronous Byzantine Broadcast algorithms for a dishonest majority","abstract":"Deterministic Byzantine Broadcast requires f+1 rounds for any f malicious processes, in the synchronous, authenticated setting. In the non-deterministic case, Katz and Koo [2] showed a lower-bound of [omega](2n=(n-f)) rounds, but it remains an open question whether the bound is tight, specically when f >/= n/2 (a dishonest majority). This thesis explores ways to improve the eciency of Byzantine Broadcast algorithms for a dishonest majority. In particular, we present an expected 10 round protocol for f = n/2, which works by constructing a hierarchy of quorums, to gather as many signatures as possible, before commitment. Finally, we offer brief commentary on how similar techniques could extend to f > n/2.","abstract_html":"Deterministic Byzantine Broadcast requires f+1 rounds for any f malicious processes, in the synchronous, authenticated setting. In the non-deterministic case, Katz and Koo [2] showed a lower-bound of [omega](2n=(n-f)) rounds, but it remains an open question whether the bound is tight, specically when f >/= n/2 (a dishonest majority). This thesis explores ways to improve the eciency of Byzantine Broadcast algorithms for a dishonest majority. In particular, we present an expected 10 round protocol for f = n/2, which works by constructing a hierarchy of quorums, to gather as many signatures as possible, before commitment. Finally, we offer brief commentary on how similar techniques could extend to f > n/2.","abstract_has_math":false,"creators":["Chan, Benjamin Yao."],"institution":"Massachusetts Institute of Technology","degree_name":"Master","degree_level":null,"degree_discipline":null,"degree_department":"Massachusetts Institute of Technology. Department of Electrical Engineering and Computer Science","school":null,"contributors":[],"advisors":["Srini Devadas."],"committee_chairs":[],"committee_members":[],"year":2019,"date_issued":"2019","date_published":"2019","updated_at":"2026-07-22T22:21:35Z","subjects":["Electrical Engineering and Computer Science."],"languages":["eng"],"rights":["MIT theses are protected by copyright. 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