MBFT: A Modular Byzantine Fault Tolerance Protocol for high adaptability

With the substantial increase in permissioned blockchain applications, various application scenarios for Byzantine Fault Tolerance (BFT) protocols are emerging. However, due to the inherent complexity of BFT, the performance improvement of BFT protocols in one aspect generally comes at the expense of degradation in others. The contradiction between the diverse requirements and the inherent characteristics of BFT makes it challenging for traditional BFT protocols to effectively address the requirements of different scenarios in practice, and the rising number of protocols and implementations often overwhelm practitioners. To propose a solution to this dilemma and improve the adaptability and effectiveness of BFT protocols in different scenarios, a novel Modular Byzantine Fault Tolerance protocol (MBFT) has been proposed, whose core idea is to utilizes modular methods to quickly and flexibly construct satisfactory BFT protocols that meet the requirements of specific scenarios. MBFT deconstructs the single-layer leader-based BFT protocol into three independent phases and provides two typical modules with different characteristics for each phase. By combining different modules, BFT protocols with different characteristics and guarantee safety, liveness and even Byzantine democracy can be obtained. The safety, liveness and Byzantine democracy of MBFT are theoretically proved, the fault resistance capability of MBFT and the relationship between the level of cluster clock synchronization and Byzantine democracy are analyzed. Extensive experimental results highlight that MBFT has high adaptability and excellent performance compared with some state-of-the-art protocols.