Fast-HotStuff: A Fast and Robust BFT Protocol for Blockchains

The HotStuff protocol is a recent breakthrough in Byzantine Fault Tolerant (BFT) consensus that enjoys both responsiveness and linear view change by creatively adding a round to classic two-round BFT protocols like PBFT. Despite its great advantages, HotStuff has a few limitations. First, the additional round of communication during normal cases results in higher latency. Second, HotStuff is vulnerable to certain performance attacks, which can significantly deteriorate its throughput and latency. To address these limitations, we propose a new two-round BFT protocol called Fast-HotStuff, which enjoys responsiveness and efficient view change that is comparable to the linear view-change in terms of performance. Our Fast-HotStuff has lower latency and is more robust against the performance attacks that HotStuff is susceptible to.