Design And Realization Of File Cryptographic System Based On Network

In recent years, with more and more computers, the computer network has had a great development. But when transmitting information rapidly and conveniently, the network makes more and more security problems. The file encryption system in this paper is an efficiency mode to ensure the information be transmitted in the network securely. And it will be very useful.As the increasing security consciousness and popularization of Internet, various technologies about security are released. Although authentication, access control, encryption and decryption and so on are used widely to protect the resources transmitted through networks. Being the key technology of information security, encryption technology is getting more and more popular. The application of the encryption technology is no longer limited in the fields of military affairs, political affairs and foreign affairs. Its commercial values and social values have been fully affirmed. So, the further research on encryption technology is very important and valuable, and it has a wide prospect.With the analysis of encryption technology, a combined encryption algorithm is proposed in this thesis to protect the security of the information transmitted over the networks. The special advantages of the symmetric algorithm and public-key algorithm are used to encrypt important information. That is, the symmetric encryption algorithm used to encrypt the information that will be transmitted, public-key encryption algorithm is used to transfer the keys that have used. At the same time, Message-Digest Algorithm is used to verify the integrity and authenticity of the information. This scheme can realize the fastly and safely transferring of the important information. It also can realize the verification about the integrity and authenticity of the information. So it has a wide prospect in the safe communication field.