中文摘要：

e-mail： cscsi@163.comJian-Bo Wang was born in Hebei Province, China, in 1972. He received his M.S. degree in computer applications from Southwest Jiaotong University in 1998, and he is currently a doctor candidate of Southwest Jiaotong University in communication ＆ information system. His research interestsinclude information security, grid and parallel computation, and security of mobile communication system. dkhe@home.swjtu.edu.cn.Da-Ke He was born in Sichuan Province, China, in 1944. He received the M.S. degree in applied mathematics from Xidian University in 1981. As a professor of Southwest Jiaotong University, his work has been concentrated in cryptography, mobile communication system security, and applied mathematics. e-mail： cnyaxu@21.cn.com.Yan Xu was born in Sichuan Province, China, in 1973. She received her M.S. degree in computer applications from Southwest Jiaotong University in 1998. Now she is a doctor candidate of Southwest Jiaotong University in traffic information engineering ＆ control. Her research interests includeinformation security and railway management information system.