1. College of Electronic Science and Technology, National University of Defense Technology, Changsha, China
2. Interdisciplinary Center for Security, Reliability and Trust (SnT), University of Luxembourg, Esch-sur-Alzette, Luxembourg
3. College of Meteorology and Oceanography, National University of Defense Technology, Changsha, China
4. School of Electronic Engineering and Computer Science, Queen Mary University of London, London, U.K.