Reaserch Of VPN Security Based On SSL Protocol

The continuous development of the globalization of information, the development of network technology is more and more mature, more refined development of information exchange, many companies and even smaller companies have their own a internal network system, through the internal network, the company can complete the internal exchange of information and office more secure. At the same time, more and more enterprises jobs done through the internal network, the increase of more office applications, more and more business users access to the network, these users secure access to the internal network to anytime, anywhere, it is above these circumstances, therefore remote access VPN access only SSL VPN technology as a more mature remote access VPN, SSL protocol provides application layer security services.At first, the thesis analyses and introduces remote access VPN technologies, including cryptography, authentication technology and the implementation of VPN protocol, which analyzes the inserurity of SSL VPN key exchange protocol handshake, mainly anonymous man-in-the-middle attack, the proposed with Kerberos authentication square method to improve the design of the system, more effectively improve system security for password guessing attacks, and proposed increase with improved Kerberos authentication protocol to reduce security risks.