Improved dynamic Byzantine Fault Tolerant consensus mechanism

The Byzantine Fault Tolerance (BFT) consensus protocols are widely used in consortium blockchain to ensure data consistency. However, BFT protocols are generally static which means that the dynamic joining and exiting of nodes will lead to the reconfiguration of the consortium blockchain system. Moreover, most BFT protocols cannot support the clearing operation of slow, crashed, or faulty nodes, which limits the application of consortium blockchain. In order to solve these problems, this paper proposes a new Dynamic Scalable BFT (D-SBFT) protocol. D-SBFT optimizes SBFT by using Distributed Key Generation (DKG) technology and BLS aggregate signature scheme. On the basis of SBFT, we add Join, Exit, and Clear algorithms. Among them, Join and Exit algorithms enable nodes to actively join and exit the consortium blockchain more flexibly. Clear can remove slow, crashed or faulty nodes from the consortium blockchain. Experimental results show that our D-SBFT protocol can efficiently implement node dynamic change while exhibiting good performance in consensus process.