作者机构:[1]School of Information Science, Guangdong University of Foreign Studies, Guangzhou 510420, China, [2]Guangdong Key Laboratory of Information Security Technology, Sun Yat-sen University, Guangzhou 510275,China
相关基金:Sponsored by the National Natural Science Foundation of China( Grant No. 60673191 and 90304011 ) and Science Innovation Term Foundation of Guangdong University of Foreign Studies ( Grant No. GW2006-AT-005 ), and Science Innovation Term Foundation of School of Informatics Guangdong University of Foreign Studies.