@inproceedings{c4cadf7d0c3545fd958eaa380e7718d7,
title = "On the round complexity of randomized byzantine agreement",
abstract = "We prove lower bounds on the round complexity of randomized Byzantine agreement (BA) protocols, bounding the halting probability of such protocols after one and two rounds. In particular, we prove that: 1. BA protocols resilient against n/3 [resp., n/4] corruptions terminate (under attack) at the end of the first round with probability at most o(1) [resp., 1/2 + o(1)]. 2. BA protocols resilient against n/4 corruptions terminate at the end of the second round with probability at most 1 − Θ(1). 3. For a large class of protocols (including all BA protocols used in practice) and under a plausible combinatorial conjecture, BA protocols resilient against n/3 [resp., n/4] corruptions terminate at the end of the second round with probability at most o(1) [resp., 1/2 + o(1)]. The above bounds hold even when the parties use a trusted setup phase, e.g., a public-key infrastructure (PKI). The third bound essentially matches the recent protocol of Micali (ITCS{\textquoteright}17) that tolerates up to n/3 corruptions and terminates at the end of the third round with constant probability.",
keywords = "Byzantine agreement, Lower bound, Round complexity",
author = "Ran Cohen and Iftach Haitner and Nikolaos Makriyannis and Matan Orland and Alex Samorodnitsky",
note = "Publisher Copyright: {\textcopyright} Ran Cohen, Iftach Haitner, Nikolaos Makriyannis, Matan Orland, and Alex Samorodnitsky.; 33rd International Symposium on Distributed Computing, DISC 2019 ; Conference date: 14-10-2019 Through 18-10-2019",
year = "2019",
month = oct,
doi = "https://doi.org/10.4230/LIPIcs.DISC.2019.12",
language = "الإنجليزيّة",
series = "Leibniz International Proceedings in Informatics, LIPIcs",
publisher = "Schloss Dagstuhl- Leibniz-Zentrum fur Informatik GmbH, Dagstuhl Publishing",
editor = "Jukka Suomela",
booktitle = "33rd International Symposium on Distributed Computing, DISC 2019",
address = "ألمانيا",
}