Transmission Technology Of Network Security

As the increase of the national network and information, more and more scholars pay great attention to network security. National construction of the PKI information is on the way. However, disposing Public Key Infrastructure widely and using CA certificate become more and more difficult because of the connatural limitation of the PKI system and CA certificate. On the point of network developing scope, it is hard for PKI to satisfy the social requirement in the future.The thesis focuses on Public Key frame. First, it introduces cryptography and its related concepts and information. It expatiates the principle and characteristic of PKI and CA certificate. Then SSL protocol and its application will be introduced as the typical application of the CA certificate. The demerit of the X.509 certificate comes next. Then it points out the reason why it is complicated using certificate for authentication. On the basis of it, the thesis analyses the limitation of the PKI system based on X.509. Then resolvement will be given.IBE(Identity Based Encryption) technologies resolve the problems of the PKI and CA certificate. Identity authentication replaces certificate and achieves the same effect as certificate. Author studies IBE technology, analyses the principle of the Ellipse Curve Cryptography(ECC) and its performance and efficiency. At last, author designs a secure electronic mail system which using Combined Public Key(CPK) arithmetic to generate user's public key and private key. To improve security and efficiency of the system, ECC arithmetic will be used for encryption, decryption and signature.The mail system designed by author combines CPK and ECC. It supports authentication, data secrecy, data integrality, secure transmission and digital signature.Jt has great running efficiency and reliability. The mail system provides a use for reference for network secure transmission model and can be consulted for various large-scale special network and application system.