A Fault-tolerant Group Key Agreement In Tree-like Based Wireless Networking

The group key agreement protocol is a basis for secure group communication,it provides users a one-time session key that is generated and shared by all user themselves through protocol interaction on a public channel.Although the tree-based wireless network is well known and widely used,it is unable to guarantee a stable and error-free communication in a long period,which causes the hardship for the construction of group key agreement in a tree-based wireless network.Therefore,research of group key agreement with fault tolerance is a subject of great importance.In this thesis,some classical key agreements are discussed.A comprehensive analysis for Diffe-Hellman algorithm is presented,particularly focusing on its security,authentication,efficiency,dynamics,scalability and data structure.In addition,based on the in-depth analysis to existing group key agreement protocols,a novel group key agreement protocol is proposed accompany with security and efficiency deductions in a tree-like wireless network.By using of the bilinear pairings and the m-tree architecture,this new protocol has superiority over other similar protocols in addition of advantage of fault tolerance.Besides,this thesis also analyzed the computational complexity and the communication complexity of the proposed protocol.In the comparison with the TGDH protocol,the proposed protocol performs better while the network delay considered as in less communications and computing overheads.The PBC library is adopted as the auxiliary function base in our protocol simulation and the C language is used to fulfill the simulation to verify the proposed protocol in a scenario of tree-like wireless network.The simulation experiments are carried out in two fashions,one without packet loss and the number of group users being 10/20/30/40/50/60/70/80/90/100 respectively.And another one of a series of experiments is conducted with the packet loss rates rising from 0% to 10% as the number of group users is fixed to 90.Both the simulations take the “average time”required to complete the setup of keys as the testing indicator.In particular,when the number of group users is 90 and the packet loss rate of the tree-like wireless network channel is 10%,the average time is about 146.76 ms,which is better than that of TGDH and demonstrates a sound capability of fault tolerance.