%0 Journal Article %J IEEE Wireless Communications %D 2004 %T Proactive key distribution using neighbor graphs %A Mishra,A. %A Min Ho Shin %A Petroni,N. L. %A Clancy,T. C %A Arbaugh, William A. %K access points %K Authentication %K authentication time %K Base stations %K Communication system security %K Delay %K graph theory %K GSM %K IEEE 802.11 handoff %K Land mobile radio cellular systems %K Message authentication %K mobile radio %K Multiaccess communication %K neighbor graph %K Network topology %K Roaming %K telecommunication security %K Telephone sets %K user mobility %K Wi-Fi networks %K wireless data networks %K Wireless LAN %K Wireless networks %X User mobility in wireless data networks is increasing because of technological advances, and the desire for voice and multimedia applications. These applications, however, require that handoffs between base stations (or access points) be fast to maintain the quality of the connections. In this article we introduce a novel data structure, the neighbor graph, that dynamically captures the mobility topology of a wireless network. We show how neighbor graphs can be utilized to obtain a 99 percent reduction in the authentication time of an IEEE 802.11 handoff (full EAP-TLS) by proactively distributing necessary key material one hop ahead of the mobile user. We also present a reactive method for fast authentication that requires only firmware changes to access points and hence can easily be deployed on existing wireless networks. %B IEEE Wireless Communications %V 11 %P 26 - 36 %8 2004/02// %@ 1536-1284 %G eng %N 1 %R 10.1109/MWC.2004.1269714