@Article{jcs.2020.011341,
AUTHOR = {Huanrong Tang, Yaojing Sun, Jianquan Ouyang},
TITLE = {Excellent Practical Byzantine Fault Tolerance},
JOURNAL = {Journal of Cyber Security},
VOLUME = {2},
YEAR = {2020},
NUMBER = {4},
PAGES = {167--182},
URL = {http://www.techscience.com/JCS/v2n4/40714},
ISSN = {2579-0064},
ABSTRACT = {With the rapid development of blockchain technology, more and more 
people are paying attention to the consensus mechanism of blockchain. Practical 
Byzantine Fault Tolerance (PBFT), as the first efficient consensus algorithm 
solving the Byzantine Generals Problem, plays an important role. But PBFT also 
has its problems. First, it runs in a completely closed environment, and any node 
can't join or exit without rebooting the system. Second, the communication 
complexity in the network is as high as O(n2), which makes the algorithm only 
applicable to small-scale networks. For these problems, this paper proposes an 
Optimized consensus algorithm, Excellent Practical Byzantine Fault Tolerance 
(EPBFT), in which nodes can dynamically participate in the network by 
combining a view change protocol with a node's add or quit request. Besides, in 
each round of consensus, the algorithm will randomly select a coordination node. 
Through the cooperation of the primary and the coordination node, we reduce the 
network communication complexity to O(n). Besides, we have added a 
reputation credit mechanism and a wrong node removal protocol to the algorithm 
for clearing the faulty nodes in time and improving the robustness of the system. 
Finally, we design experiments to compare the performance of the PBFT and 
EPBFT algorithms. Through experimental, we found that compared with the 
PBFT algorithm, the EPBFT algorithm has a lower delay, communication 
complexity, better scalability, and more practical.},
DOI = {10.32604/jcs.2020.011341}
}