Reseash On The Network Security Transmission Based On SPI And PKI

Nowadays, the scale of the computer network is growing rapidly. Communication based on network becomes the most important part of the network applications. Almost all the organizations and persons use network communication tools such as email to communicate with others. Meanwhile, there are more and more private information in the network with the expanding of the network applications, e.g. decision-making, business data, and technical document and so on. The safety of the information in the network transmission brings on broad attention. To strengthen the safety of the network information transmission is very meaningful to extend the network communication application.Under the present network structure, it's an effective solution of making the network transmission safe to encrypt the data of the network communication tools. Using safety treatment like confidentiality, integrality and undeniableness by some measure makes sure the data cannot be stolen or replaced.In order to solve the unsafe problem of network transmission, this subject researched the theory of the network security, information security, SPI and PKI. This subject synthesized SPI and PKI and brought forward a solution of information transmission security aimed at network communication applications.At first, SPI was used to obtain the TCP/IP data by changing the accessing sequence of the network protocol stack. Second, to analyze and distinguish the data of the network application and then to design the strategy of data encryption follows the characteristic of the network application. Finally, to encrypt and decrypt the information by digital envelop and digital signature using the certificate handed out by an authoritative CA based on the PKI which was built by the laboratory. The above processes ensured the confidentiality and the validity so that the target of transporting network information availably and safely was hit.The subject has been applied in an email security system. The email transmission security solution based on the subject was designed against the specialty of the email system and the email client. This solution obtained the SMTP data and POP3 data by SPI in order to find out the mail body to handle to make the email confidential. At the same time, the solution re-designed the MIME form so that the email is legal in the transmission. The validity and the feasibility of this subject are validated by applied in the email security system.