High Performance and Scalable Byzantine Fault Tolerance

With the great success of cryptocurrencies, people have paid great attention to blockchain technology and Byzantine fault tolerance (BFT) for consensus. Practical Byzantine Fault Tolerance protocol (PBFT) proposed by Castro and Liskov in 1999 is recognized as the most classic protocol for solving the Byzantine generals problem, but it still has many fatal disadvantages. Firstly, its communication complexity in the consensus process has reached O(n²), so that it can only be applied in a small-scale system. Secondly, it works in a completely enclosed environment, nodes are not allowed to participate or exit the network without restarting the system, making it difficult to get applied in the actual system. In order to solve these problem, this paper proposes the High Performance and Scalable Byzantine Fault Tolerance, an improved BFT protocol, called HSBFT. In normal case operation, the HSBFT's communication complexity is reduced to O(n), and it also has the ability to be scalable, making it adaptable to more diverse practical scenarios.