1. College of Computer Science and Technology, Qingdao University, Qingdao, China
2. BUPT-QMUL EM Theory and Application International Research Laboratory, Beijing University of Posts and Telecommunications, Beijing, China
3. Interdisciplinary Centre for Security, Reliability and Trust (SnT), University of Luxembourg, Luxembourg City, Luxembourg
4. Department of Computer Science, University of Helsinki, Helsinki, Finland
5. Department of information and Communication Engineering, The Islamia University of Bahawalpur, Bahawalpur, Pakistan
6. Department of Electrical and Computer Engineering, University of Houston, Houston, TX, USA