The Research And Design Of IPSec VPN Security Gateway Based On Reconfigurable Cipher Processing

With the development of Intenret and the network application, the network security problem is becoming one of the problems that People can't ignore. So the research of VPN (Virtual Private Network) security gateway is becoming white hot for its well done to network security problem. But if the VPN security gateway wants to be applied to market, it has to face the bottleneck between the fast speed of network transport and the relative slower speed of network data processing. Aimed at this problem, this paper makes some research so as to provide a secure, flexible, and high speed VPN gateway to fit for the increasing network security problelms and the need of development of network bandwidth.Based on the research and analysis of several related VPN resolves and aimed at their short coming, this Paper design an single chip security gateway based on the IPSec protocol. This security gateway is an embeded system and a two-NIOS II CPU structure is adopted. At this gateway the main NIOS II CPU is used to finish normal network data processing and advance IPSec processing. While the IPSec assisting CPU that is in fact another NIOS II CPU separates the IPSec processing task form the main CPU and this well resolves the problem that the main CPU has too much to do. At the same time a special reconfigurable cipher processing module is designed to accomplish the encryption and the decryption task that appears in the IPSec process fast and flexibility. Combined with the mature reconfigurable cipher processing architecture, this module is designed based on the research and analysis of several cipher algorithms that appears at the IPSec protocol. According to different configuration, This module can have different structure and finish encryption and decryption of different block cipher algorithms.The function and the performance test is done at last at this paper. The function test results show that this security gateway can finish the basic VPN function based on IPSec protocol and the performance test shows that it has a high data processing rate. It can well satisfy the demand of rate of small security gateway and has a good practicability.