Abstract
We present HotStuff, a leader-based Byzantine fault-tolerant
replication protocol for the partially synchronous model. Once
network communication becomes synchronous, HotStuff enables a correct
leader to drive the protocol to consensus at the pace of actual (vs.
maximum) network delay---a property
called \textit{responsiveness}---and with communication complexity
that is linear in the number of replicas. To our
knowledge, HotStuff is the first partially synchronous BFT
replication protocol exhibiting these combined properties.
Its simplicity enables it to be further pipelined and simplified into a
practical, concise protocol for building large-scale replication services.
HotStuff is built around a novel framework
that forms a bridge between classical BFT foundations and
blockchains. It allows the expression of other known protocols
(DLS, PBFT, Tendermint, Casper), and ours, in a
common framework.
Our deployment of \HotStuff over a
network with over 100 replicas achieves throughput and latency
comparable to that of BFT-SMaRt, while enjoying linear communication
footprint during leader failover (vs.\ cubic with BFT-SMaRt).}