Year: 2026
Type: preprint
Abstract: In Byzantine agreement with predictions each process begins with an input value and some (unreliable) prediction bits. Recently, it has been shown that with \emph{classification predictions}---where the predictions predict each process to be honest or faulty---Byzantine agreement can be completed more quickly than without predictions, circumventing the traditional $Ω(f)$ round lower bound. However, existing algorithms either handle limited prediction errors or send too many messages. Moreover, they all exchange $Ω(n^3)$ bits---enough to allow the processes to approximately agree on the classifications. In fact, it almost seemed necessary to share a significant number of prediction bits if one wanted to tolerate a high number of incorrect predictions. In this paper, we show that this high level of communication is not inherent to a round-efficient protocol with predictions. We provide an unauthenticated algorithm with near-optimal $\tilde{\mathcal{O}}(n^2)$ communication complexity and optimal resilience $t < n/3$. Furthermore, with authentication, we give an algorithm with optimal $\mathcal{O}(n^2κ)$ communication complexity (where $κ$ is a security parameter) and near-optimal resilience $t < (\frac{1}{2} - ε)n$ for any constant $ε> 0$. All of our results have optimal round complexity for any number of errors in the predictions.
Source: arXiv (Cornell University)
Institution: National University of Singapore
Subfield: Computer Networks and Communications
Field: Computer Science
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W7161120336
Cites:
Cited by:
Related to: