From Simplex to Complex

Tendermint and Simplex are both leader-based BFT protocols for partial synchrony with optimal resilience and $3\delta$ good-case latency. There is a subtle tradeoff between them: In the optimistic responsive model, Simplex obtains a worst-case view latency of $3\Delta+\delta$ while Tendermint obtains a worst-case view latency of $4\Delta+\delta$. On the other hand, Tendermint requires only a bounded number of certificates to make progress in each view, while in Simplex the number... By Ittai Abraham