Efficient Group Key Management in Wireless LANs

Group key management (GKM) refers to the actions taken to update and distribute the group key upon members joining and leaving a multicast/broadcast group. The GKM scheme defined in the IEEE 802.11 WLAN standards is not efficient because the re-keying latency grows linearly with the number of clients connected to an access point. In this paper, we apply the logical key hierarchy (LKH) and one-way function tree (OFT) algorithms to GKM in WLANs to improve its performance. Our numerical analyses show that the LKH and OFT algorithms reduce the re-keying latency of GKM in WLANs to logarithmic time.