Implementation of Improved VPN Based on SSL

摘要

An improved VPN (Virtual Private Network) system based on SSL (Secure Socket Layer) Protocol is discussed to overwhelm the defect of the traditional VPN, which is required to install client software and to do a complex operation. The concept and critical technique of VPN are discussed, and then SSL protocol architecture and the working process of the Handshake layer and the Record layer are analyzed in detail because they are very important for ensuring the network safety in the SSL. Based on the above technology, an improved VPN based on SSL protocol is designed; it overcomes the flaw of currently VPN system and enhances the security of VPN system. In this project the task of validation, encrypting and decoding is completed by Integrated Circuit (IC) card and Cipher card, moreover, a SSL proxy is added behind the corporation firewall to improve the security of SSL VPN. Moreover, this system improves not only the connected ability of communication but also the identity validation. This design of SSL VPN is more comfortable to browse the public web and it is much safer.