Research On Secure Group Communication In Ad-Hoc Networks

Ad-Hoc is an infrastructureless, amorphous and decentralized network and composed of mobile network nodes. Any centralized key management scheme or key agreement scheme is not suitable for it. Furthermore, there is no fixed central server, such as trusted third party, available for trust manager and admission controller in Ad-Hoc. The research focus of the paper is the secure group communication in Ad-Hoc networks. The main contributions of the paper are listed below.Firstly, author makes a survey and classification of mostly existing group key management schemes and group key agreement schemes;Secondly, author summarizes membership change events faced by group communication system in Ad-hoc and designs novel membership updating schemes for each membership change event. Based on these membership updating schemes, a key state-maintaining scheme is also proposed, which provides a distributed synchronization mechanism for group key agreement process using a key tree;Thirdly, Based on comparison research of BD, STR, GDH and TGDH, author proposes a novel distributed group key agreement scheme, called DOFT (Distributed Group Key Management Based on One-Way Function Tree), for Ad-hoc comprising communication nodes capable of limited computing power.Fourthly, author proposes a distributed, dynamic and hierarchical trust model for Ad-hoc, which is called reRecommendation trust model and needs offline support of group founder.Lastly, a novel group admission control scheme based on reRecommendation trust model is introduced.