Research Of Network Communication System Based On Data Encryption

Along with the enhancement of association of network communications and Internet, the correlative problems of network security, such as transmissed information, which was intercepted, tampered, retransmissed in network, were enormous imperiled to further extension in network application, this network communication system based on data encryption descends at such background.This thesis begins with an analysis on the current research status of the network system security. It points out the main problem, and then puts forward a scheme, which is used to resolve the problems, that is, encryption, authentication and remote dynamic password authentication scheme. This system includes the communication module, the cryptographic communication module and remote dynamic password authentication. It resolves the secure communication problem.As regards network communication module in this system, it analyzes the network communication TCP/IP protocol. It researches the theory and realization of the network Windows Socket, adopts the design of WinSock, which orients the connection of TCP and finally realizes the communication between two host computers in the network.As regards cryptographic communication module in this system, a mixed data encryption system is used in this thesis based on analysis the advantages and disadvantages of each algorithm. The permutation code algorithm, which is high intensity and fast, is used to encrypt transmitting plaintext. The RSA is used to encrypt the encryption key. The digital digest generated by SHA is employed to realize authentication based on introduce the technology of authentication. It can resolve the poser in the management of keys, and also guarantee the data integrity.As regards remote dynamic password authentication in this system, in the traditional password authentication insufficiency, a new scheme is used to realize that the password of the client used to log on a remote server is dynamic, which can resist the retransmission attack.Finally, I summarize the deficiency of the thesis, and analyse the flaw and the following work on the thesis.