Research On Mixed Encryption Algorithm For Enhancing IPSec VPN Data Security

The network information security is more and more important for the wide application of network technology. VPN (Virtual Private Network) is a virtual private local network to realize security and reduce cost through secure channels over the existed public communication channels, such as Internet. Data through the public network must be encrypted in VPN to insure the network information not acquired by illegal user. Encryption technology is one of the key technologies of VPN security. Encryption validity depends on the adopted encryption algorithm to a great extent. IPsec is the protocol suite used most widely among VPN architecture. Security provided by IPSec mandated encryption algorithms can't meet people's needs. So it's very important to make a research on the encryption algorithms in IPSec VPN.An improved encryption algorithm for enhancing IPSec VPN data security is investigated based on the new encryption standard AES (Advanced Encryption Standard) and the securer ECC (Elliptic Curve Cryptography).The main research tasks are as follows:(1) The fundamental theory of cryptology is summarily analysed. Related conception is introduced at first, then the principle and security of conventional cryptology, modern symmetrical encryption algorithms and asymmetrical encryption algorithms are analysed;(2) The new encryption standard AES is disgussed in this paper. First the theory of AES is presented, then its power of resisting attacks is analysed, finally we make a detailed compare of AES and DES in performance and security;(3) Elliptic Curve Cryptography is disgussed here. Mathematic fundament of ECC is presented, then its principle is disgussed, finally the efficiency and security of ECC is analysed by comparison.(4) An improved mixed encryption algorithm is proposed based on AES and ECC, mechanism of this algorithm is disgussed, then simulated security protocol isdesigned, the mixed encryption algorithm is emulated on C/C++ platform, finally analysis of its efficiency and security is disgussed through system security and efficiency test.The results show that the mixed encryption algorithm based on AES and ECC has higher security and performance than the conventional algorithm DES, and can enhance the VPN data security.