Totally distributed key management for dynamic groups in MANETs

Most existing solutions to group security in mobile ad hoc networks (MANETs) rely on a multicast core based tree (CBT) for key distribution. Such solutions, although suitable for systems with low mobility and static characteristics, are highly unsuitable for dynamic and sparse groups with changing neighborhoods. Also, tree based solutions are prone to a man-in-the-middle attack which might lead to network partitioning. Moreover, a group controller is required to control the key generation process. In this paper, we propose an entirely decentralized key generation mechanism. Using our approach, keys can be established between group members with absolutely no prior communication, as long as the group members are known. The solution relies on threshold cryptography and introduces a novel concept of node-group-key (NGK) mapping. Analytical and simulation results show appreciable performance enhancements.