1. College of Computer Science and Technology, Xi’an University of Science and Technology , Xi’an 710054 , China
2. Guangxi Key Laboratory of Cryptography and Information Security, Guilin University of Electronic Technology , Guilin 541004 , China
3. College of Safety Science and Engineering, Xi’an University of Science and Technology , Xi’an 710054 , China
4. College of Computer Science and Technology, Nanjing University of Aeronautics and Astronautics , Nanjing 211106 , China
5. School of Computing and Information Technology, University of Wollongong , Wollongong, NSW 2500 , Australia