@ARTICLE{8972381, author={Xiao, Yang and Zhang, Ning and Lou, Wenjing and Hou, Y. Thomas}, journal={IEEE Communications Surveys Tutorials}, title={A Survey of Distributed Consensus Protocols for Blockchain Networks}, year={2020}, volume={22}, number={2}, pages={1432-1465}, doi={10.1109/COMST.2020.2969706}}