HotStuff-2 vs. HotStuff: The Difference and Advantage
Siyuan Zhao, Yanqi Wu, Zheng Wang
TL;DR
This work analyzes Byzantine consensus by comparing HotStuff and its successor HotStuff-2 under the standard condition $n \ge 3f + 1$. It implements both protocols in a common framework and conducts experiments to evaluate runtime under varying communication delays, node counts, and Byzantine node counts, highlighting the effect of design changes such as linear view changes, optimistic responsiveness, and the Pacemaker-based view synchronization. The main findings show that HotStuff-2 reduces one voting round and preserves linear view changes and optimistic responsiveness, while introducing a happy-path two-phase voting and adaptive synchronization to maintain safety in adverse conditions. Overall, HotStuff-2 demonstrates practical gains in usability and performance, particularly in networks with a low proportion of Byzantine nodes, informing protocol choice based on network conditions.
Abstract
Byzantine consensus protocols are essential in blockchain technology. The widely recognized HotStuff protocol uses cryptographic measures for efficient view changes and reduced communication complexity. Recently, the main authors of HotStuff introduced an advanced iteration named HotStuff-2. This paper aims to compare the principles and analyze the effectiveness of both protocols, hoping to depict their key differences and assess the potential enhancements offered by HotStuff-2.