Affiliation: | 1.Institute of Computer Science Theory, School of Data and Computer Science,Sun Yat-sen University,Guangzhou,China;2.The Guangdong Key Laboratory of Information Security Technology,Sun Yat-sen University,Guangzhou,China;3.School of Mathematics and Physics,Jiangsu University of Technology,Changzhou,China;4.Instituto de Telecomunica??es, Departamento de Matemática,Instituto Superior Técnico,Lisbon,Portugal |