DKEM: Secure and efficient distributed key establishment protocol for wireless mesh networks

In this paper, we propose an efficient and secure key establishment protocol that is tailored for Wireless Mesh Networks. The protocol is based on identity-based key establishment, but without the utilization of a trusted authority for private key generation. Instead, this task is performed by the collaboration of mesh nodes; a number of users exceeding a certain threshold form a coalition to generate private keys for the network users. We performed simulative performance evaluation in order to show the effect of both the threshold value and the network size, i.e., total number of nodes, on the latency of key establishment and on the success percentage of user private key generation. Results reveal a trade-off between resiliency and efficiency; increasing the threshold value also increases the resiliency of the network, but negatively effects its latency and success percentage. For the threshold values that are smaller than 10 and for a minimum of 40 mesh nodes, at least 93% of the user private keys can be computed within at most 2 min. We also discuss the security of our protocol. We show that our protocol is secure against both outsider malicious and insider semi-honest adversaries.