1. Department of Computing Security, Rochester Institute of Technology, 6925 Rochester, New York, United States
2. School of Computer Science and Engineering, Central South University, 12570 Changsha, Hunan, China
3. Computer and Information Sciences, University of Delaware, Newark, Delaware, United States, 19716
4. Electrical, Computer, and Energy Engineering, Arizona State University, Tempe, Arizona, United States, 85287-7206