Analysis On VPN Technique Based On IPSec And Its Security

With the wide application of the Internet technology, we can exchange and share information conveniently, while computer systems are confronted with unprecedented hidden troubles of security. For example, information in transmission may be peeked or tampered. Local network may suffer illegal access and attack. The network information security becomes the focus for us. The private network can ensure information transmission securely, but it costs too much. To reduce the cost of network management ,the desire for building local network with Internet technology is strong. The technology of virtual private network(VPN) develops rapidly under this ground.This dissertation described, analyzed the feature, mode, protocol, and application of VPN and provided ideas for improvements based on the existing problems. In detail, this dissertation includes the following aspects:1 , VPN Tunneling TechniquesThis dissertation described the fundamentals of VPN tunneling techniques and made a comparison and an analysis of the main tunneling protocols: PPTP, L2TP and IPSec.2, Security of VPNSecurity is the primary consideration while designing and building a VPN. As IPSec is the key technology to ensure security, this dissertation analyzed the security of IPSec based on the description of the IPSec architecture.3, Layered IPSecWith the extension of network applications in various fields and the increasing demand of overall network performance ,many new services and applications have been introduced in Internet. However ,the "end to end" security mechanisms used by IPSec have brought problems to these new services and applications. This dissertation described and analyzed these problems, evaluated several possible ways, and presented a new IPSec architecture to solve these problems.At last, this dissertation described the development of VPN and IPSec protocol.