1. Key Laboratory of Communication and Information Systems, Beijing Municipal Commission of Education, Beijing Jiaotong University, Beijing, PR China
2. Department of Computer Science and Electrical Engineering, School of Computer and Engineering, University of Missouri, Kansas City, USA
3. Guangxi Key Laboratory of Cryptography and Information Security, Guilin University of Electronic Technology, Guilin, PR China
4. Fujian Provincial Key Laboratory of Network Security and Cryptology, Fujian Normal University, Fuzhou, PR China
5. School of Engineering, University of Melbourne, Melbourne, Australia