1. State Key Laboratory of Integrated Services Networks, Xidian University, Xi’an, China
2. Shaanxi Key Laboratory of Blockchain and Secure Computing, Xidian University, Xi'an, China
3. Guangzhou Institute of Technology, Xidian University, Guangzhou, China
4. Department of Computer and Network Engineering, The University of Electro-Communications, Tokyo, Japan
5. Department of Applied Informatics, Silesian University of Technology, Gliwice, Poland