PRO-HotStuff: A Practical and Robust Blockchain Consensus Mechanism

Consensus mechanism is the foundational protocol for achieving distributed consistency among replicas in a blockchain network. A well-designed consensus mechanism needs to balance performance such as complexity, consensus mechanism initiative and dynamic adaptability. Based on Hot-Stuff (a BFT-like consensus with O(n) complexity), we propose a practical and robust consensus mechanism, namely Practical and Robust HotStuff, denoted as PRO-HotStuff. Firstly, PRO-HotStuff redesigns a pacemaker that simultaneously supports replica synchronization and quorum certificate caching, and thus achieves practical view change with O(n) communication complexity while avoiding the additional phase introduced by HotStuff. Secondly, PRO-HotStuff gives the leader election basis by introducing the theory of planed behavior (TPB) and a reputation mechanism. It facilitates restricting the malicious replicas while encouraging the trustworthy replicas, thus to enhance the robustness of PRO-HotStuff. Thirdly, the implementation design of PRO-HotStuff as well as its reconfiguration mechanism for dynamic adaptability is presented. Proofs of correctness of PRO-HotStuff are also provided. Finally, experiments demonstrate that compared to existing HotStuff-like consensus mechanisms, PRO-HotStuff has significant advantages in terms of consensus performance, security, and dynamic adaptability.