Research And Design Of The Link Layer Encrypting Network Card Based On 802.10 Protocol

With the improvement of people's realization on network security, the security problem of inner-network has gradually become a popular issue of current research of the world. From the aspect of work efficiency and the security, this article analyzed several security projects to resolve the LAN data transmission currently. And then a kind of project of link layer encrypting network card based on IEEE 802.10 protocol had been proposed in this thesis based on the research of link layer security protocols. We analyzed the process of hardware operation and controlling from the aspect of data transmission processing and key management respectively, and emphatically researched on the designing technology of encrypting network card controller.There are two parts included in our encrypting network card controller: local-bus controller and inner-bus controller according to the different functions. An encrypting network card local-bus controller which adopted multiple state machine mode was designed based on the comparison of common designing methods of controllers, and an encrypting network card inner-bus micro controller which has the function of dictate jump and dictate coding was also devised aimed at the functionality and flexibility request of inner-bus. The micro controller can support the function of program jump and sub-program transfer via the special address generating logic designed. Compared with microcode controller, the micro controller improved the flexibility of dictate compiling. At the same time, codes that have the same function were devised as sub-programs, through which the micro controller saved the resources of dictate memorizer. Furthermore, the micro controller supported direct data transmission among peripheral equipments, omitted DMA initialization process compared with traditional DMA direct data transmission mode and improved the efficiency of data transmission.Finally, the test software was designed. We tested the function and performance of the prototype card of link layer encrypting network card, and therefore validated the feasibility of our design. After comparing the test results with theory values, the reason of errors was analyzed. The result of the research in this thesis has practical value for designing and exploiting link layer encrypting network card.