1. School of Information Science, Luoyang Normal University, Luoyang, China
2. College of Cyber Security, Jinan University, Guangzhou, China
3. Faculty of Computer Science, University of New Brunswick, Fredericton, NB, Canada
4. State Key Laboratory of Integrated Services Networks, Xidian University, Xi’an, China
5. School of Computer and Communication, Lanzhou University of Technology, Lanzhou, China