Parallel Byzantine Consensus Based on Hierarchical Architecture and Trusted Hardware

Byzantine fault-tolerant (BFT) state machine replication (SMR) is adopted to support blockchain consensus by tolerating arbitrarily faulty behaviours. However, the inherent complexity of BFT protocols makes existing BFT protocols hard to adapt to large-scale applications that require high scalability and performance. In this paper, we propose a BFT parallelism protocol designed to enhance its scalability by using a hierarchical multi-committee architecture. It also encompasses a cross-layer consensus operation flow to improve safety and support trusted execution environments (TEEs). Our proposed approach allows the lower bound on the number of peers to be reduced to $2f+1$ . We show the value of our proposed protocol in comparison to other state-of-the-art BFT protocols through experiments and performance evaluations on a testbed built on a cloud platform. The proposed protocol demonstrates a remarkable level of scalability, capable of accommodating a growing number of peers. Additionally, it exhibits improved performance when contrasted with HotStuff and FastBFT, with approximately 100% and 200% enhancements, respectively.