The Scheme Of Disconnection And Its Implementation In GAP System

With the development of e-Commerce and e-Government, the method of Physical cutoff, which has been used in the protection of confidential information, has disturbed the development of the protection. The confidential server or the desktop also need exchange information with outside. We must make sure the confidential data are not only stored separately in a certain region, but also used by authorized users of outside. This technique is named "security isolation and information exchange technology", also called "GAP". Currently the internal and external researches in this area are still at the beginning, mostly stay at some specified solutions. There are not systematic and general technological resources, especially the research of triple host architecture.This thesis focuses on the disconnection solution in GAP system. At the front part of thesis, firstly states the original point and the value of the technique, and briefly introduces its current research situation. Then the objective and applied situation of GAP are interpreted, as well as its prototype, theory and model. After that this thesis advances a framework based on the triple-host mode and defines function and structure of each subsystem. At the second half of the thesis, by the in-depth research on the application of IEEE 1394-1995, a switcher and its higher subsystem for disconnection on physical layer and data exchange are designed, as well as its structure and function are stated in details. Finally, the function, structure and process of each module are described respectively. In addition, this thesis discusses and researches on the general disconnection solutions and the security of GAP system itself.The main study work and conclusions of the thesis are summarized as follow:1.The summarization of GAP. Beginning with physical cutoff technique, the thesis firstly describes the contradiction between the physical cutoff and the development of e-commerce and e-government. Then introduces the original point of the technique, describes three familiar architecture of GAP, and provides its scheme and the internal and external researches in this area. 2. Architecture Firstly, generally describes the objective and application situation, states the prototype, theory, model and its glossary. Secondly, provides a triple-host-mode solution and the structure in modules. Finally, defines the function, structure and exchanged data. 3. Structure of Transmit Sub System At first, the thesis introduces the transmit equipment and medium, and expatiates on its theory, model and protocol stack. By analyzing the electrical characteristic of the cable, it provides the theory of switcher, which is used to control 1394 card. After that, describes the architecture of Transmit Sub System, defines its function, interface, buffer pool and package format, and analyzes and expatiates on the function, structure and process of each sub module in details. At last, states the scheme of error recovery in GAP system. 4. Questions and Discussion The thesis discusses the general disconnection solution, including the rules for designing data exchange module and disconnection module. Then the self-security of the GAP system is researched, as well as the mechanism for securing the Transmit Layer. Additionally, it introduces the security on Physical Layer and the current authorization measures. At last, the conclusion of the thesis and the prospect of the GAP technique are made.