School of Mathematics and Statistics Ludong University Yantai 264025 China;
Key Laboratory of Information Security Guangzhou University Guangzhou 510006 China;
China-USA Computer Science Research Center Nanjing University of Information Science and Technology Nanjing 210044 China;
Shield Lab Singapore Research Center of Huawei 117674 Singapore;
Department of Mathematics Hangzhou Normal University Hangzhou 311121 China;