Research And Implementation Of Key Technologies In The Survivable System Based On P2P Technology

While the network goes increasingly deep into the social life, it brings us lots of conveniences, as well as many hidden troubles on security.When some important sections cease providing services due to the attack, such as energy, power supplying, finance, bank, military and so on, the loss it brings us will be difficult to estimate, and even threats the survive of the country. Thus, people start to do a lot of research on the survivability of the system. The architecture of the traditional system is mainly the client/server architecture. The emergence of the Naspster, Gnutella and Freenet arouses people's attention on the P2P technology. Nowadays, people apply the P2P technology to many fields, and the main appliances include information sharing, cooperating, distributed computing, realtime communicating, information searching, WAN storing system, and so on. This dissertation researches the survivable system based on the P2P technology and its key technologes, and mainly analyzes the appliance of the P2P technology to survivability. The chief work includes the following aspects:Firstly, this dissertation analyzes the advantage which the P2P technology has on survivability researching, summarizes the status quo of survivability researching, and researches the theory related to the survivable system and the P2P technology.Secondly, the survivable system based on the P2P technology is designed in this dissertation. This dissertation analyzes the problems in setting up the P2P network in detail and puts forward the solution to these problems, and finally researches the key technologies of the system in depth: the mechanism of communicating and routing, the infomation dispensing algorithm, the mechanism of multiple downloading and the mechanism of security authenticating.Thirdly, this dissertation proposes the fast information dispensing algorithm called FastBroadcast, and analyses and tests the performance of the algorithm. The result of the test indicates that this algorithm reduces the height of the spanning tree of information dispensing, so that reduces the time of information dispensing and improves the performance of the system.Finally, the survivable prototype system called LiveNet is implemented in this dissertation. The result of testing the performance of the system indicates that, the time which peers cost on downloading increases very much when the number of the peers increases at a rapid rate in the model of the centralized server, and the performance declines very fast at the same time. LiveNet, however, maintains good performance even when the size of the network is very large.From what has been done above, this dissertation designs and implements a reliable and stable model of message routing, and the system not only can dispense the secure information fast and safely, but also can adapt to multiple downloading requests of thousands of peers. Furthermore, the survivability of the system in the malicious environment has been improved a lot as well. The products in this dissertation are applied in the project 863 and contribute to the successfully completement of the project.