1. Key Laboratory of Cryptologic Technology and Information Security, Ministry of Education, and the School of Cyber Science and Technology, Shandong University, Qingdao, China
2. Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen, China
3. Department of Computer Science and Technology, Harbin Institute of Technology, Shenzhen, China
4. Huawei Technologies Company Ltd., Shenzhen, China