The National Natural Science Foundation of China under Grant Nos. 61702294, 61572267 国家自然科学基金;the Natural Science Foundation of Shandong Province under Grant No. ZR2016FQ02 山东省自然科学基金;the Open Research Project of State Key Laboratory of Information Security under Grant Nos. 2016-MS-23, 2017-MS-21 信息安全国家重点实验室开放课题