Paper 2025/303 Original: eprint.iacr.org/2025/303 ↗
Asynchronous Algorand: Reaching Agreement with Near Linear Communication and Constant Expected Time
Abstract
The celebrated Algorand protocol solves validated byzantine agreement in a scalable manner in the synchronous setting. In this paper, we study the feasibility of similar solutions in the asynchronous setting. Our main result is an asynchronous validated byzantine agreement protocol that we call Asynchronous Algorand. As with Algorand, it terminates in an expected constant number of rounds, and honest parties send an expected $O(n ~\mathsf{polylog}~n)$ bits, where $n$ is the number of parties. The protocol is resilient to a fully-asynchronous weakly-adaptive adversary that can corrupt a near-optimal number of parties ($<(1/3-\epsilon) n$) and requires just a VRF setup and secure erasures. A key innovation in Asynchronous Algorand is a rather simple but surprisingly effective method to do \textit{committee-based role assignment} for asynchronous verifiable secret sharing in the YOSO (You Only Speak Once) model. This method achieves near-optimal resilience and near-linear communication complexity while relying solely on a verifiable random function (VRF) setup and secure erasures.
Metadata
- Available format(s)
PDF- Category
- Cryptographic protocols
- Publication info
- Preprint.
- History
- 2025-02-20: last updated
- 2025-02-20: published
- Short URL
- https://ia.cr/2025/303
- License
- https://creativecommons.org/licenses/by/4.0/
BibTeX
@misc{cryptoeprint:2025/303,
author = {Ittai Abraham and Eli Chouatt and Ivan Damgård and Yossi Gilad and Gilad Stern and Sophia Yakoubov},
title = {Asynchronous Algorand: Reaching Agreement with Near Linear Communication and Constant Expected Time},
howpublished = {Cryptology {ePrint} Archive, Paper 2025/303},
year = {2025},
url = {https://eprint.iacr.org/2025/303}
}