Speeding Dumbo: Pushing Asynchronous BFT Closer to Practice
Bingyong Guo, Yuan Lu, Zhenliang Lu, Qiang Tang, Jing Xu, Zhenfeng Zhang
Abstract
Asynchronous BFT consensus can implement robust mission-critical decentralized services network without relying on any form of timing assumption. Starting from the work of HoneyBadgerBFT (CCS 2016), several studies tried to push asynchronous BFT towards practice. In a recent work of Dumbo (CCS 2020), they redesigned the protocol backbone and used one multi-valued validated Byzantine agreement (MVBA) to replace n concurrent asynchronous binary agreement (ABA) protocols and dramatically improved the performance. Despite those efforts, asynchronous BFT protocols remain to be slow, and in particular, the latency is still quite large. There are two reasons contributing to the inferior performance: (1) the reliable broadcast (RBC) protocols still incur substantial costs; (2) the MVBA protocols are quite complicated and heavy, and all existing constructions need dozens of rounds and take the majority of the overall latency.