,
Diana Ghinea
,
Roger Wattenhofer
,
Floris Westermann
Creative Commons Attribution 4.0 International license
Convex Consensus (CC) allows a set of parties to agree on a value v inside the convex hull of their inputs with respect to a predefined abstract convexity notion, even in the presence of byzantine parties. In this work, we focus on achieving CC in the best-of-both-worlds paradigm, i.e., simultaneously tolerating at most t_s corruptions if communication is synchronous, and at most t_a ≤ t_s corruptions if it is asynchronous. Our protocol is randomized, which is a requirement under asynchrony, and we prove that it achieves optimal resilience. In the process, we introduce communication primitives tailored to the network-agnostic model. These are a deterministic primitive allowing parties to obtain intersecting views (Gather), and a randomized primitive leading to identical views (Agreement on a Core-Set). Our primitives provide stronger guarantees than previous counterparts, making them of independent interest.
@InProceedings{constantinescu_et_al:LIPIcs.DISC.2024.15,
author = {Constantinescu, Andrei and Ghinea, Diana and Wattenhofer, Roger and Westermann, Floris},
title = {{Convex Consensus with Asynchronous Fallback}},
booktitle = {38th International Symposium on Distributed Computing (DISC 2024)},
pages = {15:1--15:23},
series = {Leibniz International Proceedings in Informatics (LIPIcs)},
ISBN = {978-3-95977-352-2},
ISSN = {1868-8969},
year = {2024},
volume = {319},
editor = {Alistarh, Dan},
publisher = {Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
address = {Dagstuhl, Germany},
URL = {https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.DISC.2024.15},
URN = {urn:nbn:de:0030-drops-212411},
doi = {10.4230/LIPIcs.DISC.2024.15},
annote = {Keywords: convex consensus, network-agnostic protocols, agreement on a core-set}
}