General Design On Embedded Small Proxy Secure Gateway And Research On Key Circuit

Alone with the improvement of the information construction in our country, the network becomes a important implement of information exchange more and more, impacted on every fields of society life; due to the TCP/IP congenital defect, lawless users in the network are likely to threaten on the network security seriously at any moment; especially in the electron government affair system construction, information exchange safely and conveniently between the external net, the internal net and the private net is a problem needed to solve urgently. However, many security defense measures at the present are still in the superficial phase, so a depth defense system considered all factors synthetically—"a isolated secure gateway shielded subnet" emerges as the times require.Firstly, the paper presents the "physical isolation" concept and technology related in the domestic and overseas area these days, points out that the secure gateway is the best solution; then gives the general description about the secure gateway collectively, include the key technology , system and structure about the secure gateway; and educes the main work in the task thereby—the design of embedded small isolation secure gateway shielded subnet, summarizes its idea and scheme—a single host computer + special FPGA circuit board in the bottom layer; the main work in the paper emphasizes on the design of the module grade and the simulation verification of special FPGA circuit board about the design of the hardware system; the paper talks about the design thought about the author in the detail particularly about the FPGA module circuit in the bottom layer of the secure gateway and testifies the modules 'function combined with the simulation graph, in the end , sums up the paper entirely.