Tree-based group key agreement framework for mobile ad-hoc networks

Design of protocols for mobile ad-hoc networks (MANETs) is generally tricky compared to wired networks, because on the one hand the increased communication constraints given by the limited bandwidth and frequent network failures, and on the other hand the additional computation and memory constraints due to performance limitations of mobile devices must be considered. We focus on the problem of the establishment of the shared key in mobile ad-hoc groups. This task can be achieved by means of a contributory group key agreement (CGKA) protocol that allows group members to compute the group key based on their individual contributions providing verifiable trust relationship between participants. As shown in this paper there exists currently no CGKA protocol for mobile ad-hoc networks that provides an optimal trade-off between communication and computation efficiency. Based on the comparison results of most suitable CGKA protocols we propose a new framework for the group key agreement in mobile ad-hoc networks. Theoretical analysis and experimental results show that our framework achieves optimal communication and computation efficiency compared to other protocols.