Accelerating PBFT in IoT blockchain applications by overlapping consensus rounds

In this paper, we describe a mechanism to improve the speed of the Practical Byzantine Fault Tolerance (PBFT) consensus protocol in a multi-leader setting by overlapping the COMMIT and PREPREPARE stages where applicable. We analyze the performance of the proposed mechanism using a probabilistic model and show that it achieves high throughput at high block arrival rates, with cycle time approaching one maximum round-trip time between the nodes on the consensus committee. The mechanism is suitable for blockchain applications since invalid blocks are detected and rejected directly by the consensus protocol without the need to retract the decisions already reached.