You are looking at a specific version 20190612:185439 of this paper. See the latest version.

Paper 2019/692

Synchronous Consensus with Optimal Asynchronous Fallback Guarantees

Erica Blum and Jonathan Katz and Julian Loss

Abstract

Typically, protocols for Byzantine agreement (BA) are designed to run in either a synchronous network (where all messages are guaranteed to be delivered within some known time $\Delta$ from when they are sent) or an asynchronous network (where messages may be arbitrarily delayed). Protocols designed for synchronous networks are generally insecure if the network in which they run does not ensure synchrony; protocols designed for asynchronous networks are (of course) secure in a synchronous setting as well, but in that case tolerate a lower fraction of faults than would have been possible if synchrony had been assumed from the start. Fix some number of parties $n$, and $0 < t_a < n/3 \leq t_s < n/2$. We ask whether it is possible (given a public-key infrastructure) to design a BA protocol that (1) is resilient to $t_s$ corruptions when run in a synchronous network and (2) remains resilient to $t_a$ faults even if the network happens to be asynchronous. We show matching feasibility and infeasibility results demonstrating that this is possible if and only if $t_a + 2\cdot t_s < n$.

Metadata
Available format(s)
PDF
Category
Cryptographic protocols
Publication info
Preprint. MINOR revision.
Keywords
Byzantine agreement
Contact author(s)
jkatz2 @ gmail com
History
2021-09-27: last of 5 revisions
2019-06-12: received
See all versions
Short URL
https://ia.cr/2019/692
License
Creative Commons Attribution
CC BY
Note: In order to protect the privacy of readers, eprint.iacr.org does not use cookies or embedded third party content.