Approximate Agreement Algorithms for Byzantine Collaborative Learning

Loading...
Thumbnail Image

Access rights

openAccess
CC BY
publishedVersion

URL

Journal Title

Journal ISSN

Volume Title

A4 Artikkeli konferenssijulkaisussa

Major/Subject

Mcode

Degree programme

Language

en

Pages

12

Series

SPAA 2025 - Proceedings of the 2025 37th ACM Symposium on Parallelism in Algorithms and Architectures, pp. 89-100

Abstract

In Byzantine collaborative learning, n clients in a peer-to-peer network collectively learn a model without sharing their data by exchanging and aggregating stochastic gradient estimates. Byzantine clients can prevent others from collecting identical sets of gradient estimates. The aggregation step thus needs to be combined with an efficient (approximate) agreement subroutine to ensure convergence of the training process. In this work, we study the geometric median aggregation rule for Byzantine collaborative learning. We show that known approaches do not provide theoretical guarantees on convergence or gradient quality in the agreement subroutine. To satisfy these theoretical guarantees, we present a hyperbox algorithm for geometric median aggregation. We practically evaluate our algorithm in both centralized and decentralized settings under Byzantine attacks on non-i.i.d. data. We show that our geometric median-based approaches can tolerate sign-flip attacks better than known mean-based approaches from the literature.

Description

Publisher Copyright: © 2025 Association for Computing Machinery. All rights reserved.

Other note

Citation

Cambus, M, Melnyk, D, Milentijević, T & Schmid, S 2025, Approximate Agreement Algorithms for Byzantine Collaborative Learning. in SPAA 2025 - Proceedings of the 2025 37th ACM Symposium on Parallelism in Algorithms and Architectures. ACM, pp. 89-100, Annual ACM Symposium on Parallelism in Algorithms and Architectures, Portland, Oregon, United States, 28/07/2025. https://doi.org/10.1145/3694906.3743343