Design And Implementation Of A Secure Communication Platform Based On Wireless Ad-hoc Network

A wireless Ad-hoc network is a collection of mobile hosts with wireless transceiver. It is a multi-hop and instant self-organization network without the aid of any established infrastructure or centralized administration. It is difficult to set up a center to distribute key because of its instant, dynamically changing topology, so the security of wireless Ad-hoc networks has become a hot spot. In this thesis, the security issues in wireless Ad-hoc networks are investigated, aiming at designing and implementing a secure communication platform for peer groups. Some related key problems are also studied.Firstly, the thesis analyses the GDH.2 (Group Diffie-Hellman) protocol, and points out its deficiencies, then discusses an extended contributory conference key agreement protocol--MGDH. 2 proposed by the researchers at the Institute of Mobile Communication in Southwest Jiaotong University. Compared with GDH.2, the identity of the participants and the integrality of transmitted data are verified in the scheme, the final conference key is affirmed. Moreover, the security of the new protocol is improved at a slight cost in computation and communication overheads.Secondly, a secure communication platform based on peer to peer network is designed and implemented, using Microsoft Visual C++6.0 as development tool. The platform puts emphasis on the implementation of M-GDH.2 protocol, and realizes such functions as follows: peer to peer network connection, dynamically displaying network topology , key generation, secure communication, help-online and so on. The platform is suitable to the condition that a small group of people would like to exchange the information instantly among their laptop computers without the key distribution center.Because M-GDH.2 is only designed for three users, in order to make the platform more practical, the author designs a key distribution strategy that isappropriated for multiuser environment at a slight cost of reducing the security, which allows each of the participants has the ability to generate a random key and distribute it to the others.Finally, the thesis summarizes the work done during the MSc research, and puts forward the possible extensions and improvements to the existing system.