Cryptography Applied Research In Network Information Security Technology

With the popularity of network, the security of computer network becomes an important matter to affect the efficient of network, and this requires more security of network. A secure network system should ensure the integrality and confidentiality of the data were been transimitted, and cannot deny who transmit them. There are a lot of techniques to safeguard the security of the network, and data encryption techniques are the most core measure. Encryption techniques are the mainconstitutes of the cryptography in modern times. There are main two systems, which are traditional cipher system, and public key cipher system in the encryption techniques. Public key cipher system is applied abroadly in data encryption and digital signaturePKI (Public Key Infrastructure) is a new secure technology, which take advantage of public-key technique to provide a set of secure basic terrace,and make use of which the user can communicate safely. The basic technology of PKI include encipher digital signature data integrity mechanism digital envelope double digital signature, digital certificate etc. The article mainly research cryptography applying in digital encrypts technique base on PKI and mainly includes three steps: public key encipher, digital signature and key distribution.At first I analyse the tendency of cryptography development and a few encrypt algorithm include public key algorithm - RSA. At last I set up a system of public key encipher based on PKI and include data encipher and digital signature. I propose a sort of modified RSA algorithm in order to improve the calculational rate of traditional RSA algorithm. In order to adapt to the development of network, I adopt group linearity signature, which is a less network-spending algorithm. At last I adopt public key certificate to manage and distribute the public key.