中文摘要：

该文针对当前短消息系统的明文传输方式带来的一系列不安全因素（如数据包被窃取、篡改等）,提出基于IPSec VPN的安全短消息系统。将IPSec VPN的安全机制引入短消息系统,研究表明此方法对提高短消息系统的安全性是必要的。

英文摘要：

With some insecure factors existing SMS（Short Message Service） system which is transferred by plain text, such the short message will be filched, intercepted and sophisticated, IPSec VPN based on Secure SMS system will be proposed and its secure mechanism will be implemented. The study shows the mechanism in SMS system is necessary to ensure the secure of the SMS system.