Key Technology Of Firewall Based On Content Filter

With the fast development of computer technology, communication technology and application, the information network is booming. In the information society, society becomes more and more dependence on computer network, and network influences society more and more. With the boosting of diversified network operation, network security becomes more and more important. So network security becomes an important research and development direction in the field of data communication, and a hot in the field of computer and communication. People pay more and more attention on network security.This paper first gives the definition of network security, discusses key technology of network security. Firewall is the footstone of network security. This paper second comes down to the correlative knowledge of firewall, which includes the basic concept and class of firewall. Final this paper brings forward a firewall based on content filter.The firewall based on content filter is a firewall, which employs the proxy mechanism, filters information based on IP address and encrypts/decrypts information. This firewall mostly implements two functions: first filer the data information on network and modify the IP address database based on the result of filtering; second encrypt/decrypt data information. There are three modules in this firewall: IP address security determinant module, content filter module and encryption/decryption module. These modules integrated each other to implement the function of this firewall. IP address security determinant module intercept and capture the IP package and parse it, then determinant its security based on IP address database, thus management dynamic IP address database is crucial in this module. Content filter module examines the security of the information in the package, and feedback a signal to the IP address security determinant module. Encryption/decryption module employs ECC to implementing encryption/decryption. As a key technology of the firewall, we will particular discuss the cryptography in this paper.The firewall based on content filter is an open system, which can expands else functions. Certainly, the firewall proposed in this paper only implement two parts of all its functions, it needs further research to perfect the firewall.