1. Key Laboratory of Cryptologic Technology and Information Security, Ministry of Education, and School of Software, Shandong University, Jinan, China
2. School of Electrical Engineering and Computer Science, University of California at Merced, Merced, CA, USA
3. School of Computer Science and Engineering, Nanyang Technological University, Jurong West, Singapore
4. School of Software, Shandong University, Jinan, China
5. Key Laboratory of Cryptologic Technology and Information Security, Ministry of Education, and School of Cyber Science and Technology, Shandong University, Jinan, China