Funding for this research was provided by:
National Natural Science Foundation of China (61672499, 61772502, 61972382)
the Key Special Project of Beijing Municipal Science & Technology Commission, China (Z181100003218018)
the Natural Science Foundation of Inner Mongolia, Open Foundation of State Key Laboratory of Networking and Switching Technology of China (SKLNST-2016-2-09)
the SV-ICT Blockchain & DAPP Joint Lab of China
the ICT-SSC Blockchain Joint Lab of China
Article History
Received: 23 February 2018
Accepted: 18 May 2018
First Online: 13 November 2019
Compliance with ethics guidelines
: Lei YU, Xiao-fang ZHAO, Yan JIN, Heng-yi CAI, Bo WEI, and Bin HU declare that they have no conflict of interest.