On Fast and Accurate Detection of Unauthorized Wireless Access Points Using Clock Skews Export

@article{jana:detection, abstract = {We explore the use of clock skew of a wireless local area network access point (AP) as its fingerprint to detect unauthorized APs quickly and accurately. The main goal behind using clock skews is to overcome one of the major limitations of existing solutions- the inability to effectively detect Medium Access Control (MAC) address spoofing. We calculate the clock skew of an AP from the IEEE 802.11 Time Synchronization Function (TSF) timestamps sent out in the beacon/probe response frames. We use two different methods for this purpose - one based on linear programming and the other based on least square fit. We collect TSF timestamp data from several APs in three different residential settings. Using our measurement data as well as data obtained from a large conference setting, we find that clock skews remain consistent over time for the same AP but vary significantly across APs. Furthermore, we improve the resolution of received timestamp of the frames and show that with this enhancement our methodology can find clock skews very quickly, using 50-100 packets in most of the cases. We also discuss and quantify the impact of various external factors including temperature variation, virtualization, clock source selection and NTP synchronization on clock skews.}, address = {Los Alamitos, CA, USA}, author = {Jana, Suman and Kasera, Sneha K.}, citeulike-article-id = {5687409}, citeulike-linkout-0 = {http://doi.ieeecomputersociety.org/10.1109/TMC.2009.145}, citeulike-linkout-1 = {http://dx.doi.org/10.1109/TMC.2009.145}, doi = {10.1109/TMC.2009.145}, issn = {1536-1233}, journal = {IEEE Transactions on Mobile Computing}, keywords = {80211, clock\_skew, crawdad, rogue-ap, timing, uw\_sigcomm2004, wireless-security}, number = {1}, posted-at = {2009-08-31 10:09:26}, priority = {2}, publisher = {IEEE Computer Society}, title = {On Fast and Accurate Detection of Unauthorized Wireless Access Points Using Clock Skews}, url = {http://dx.doi.org/10.1109/TMC.2009.145}, volume = {99}, year = {5555} }

TY - JOUR ID - jana:detection L3 - citeulike-article-id:5687409 N2 - We explore the use of clock skew of a wireless local area network access point (AP) as its fingerprint to detect unauthorized APs quickly and accurately. The main goal behind using clock skews is to overcome one of the major limitations of existing solutions- the inability to effectively detect Medium Access Control (MAC) address spoofing. We calculate the clock skew of an AP from the IEEE 802.11 Time Synchronization Function (TSF) timestamps sent out in the beacon/probe response frames. We use two different methods for this purpose - one based on linear programming and the other based on least square fit. We collect TSF timestamp data from several APs in three different residential settings. Using our measurement data as well as data obtained from a large conference setting, we find that clock skews remain consistent over time for the same AP but vary significantly across APs. Furthermore, we improve the resolution of received timestamp of the frames and show that with this enhancement our methodology can find clock skews very quickly, using 50-100 packets in most of the cases. We also discuss and quantify the impact of various external factors including temperature variation, virtualization, clock source selection and NTP synchronization on clock skews. IS - 1 JF - IEEE Transactions on Mobile Computing SN - 1536-1233 AD - Los Alamitos, CA, USA TI - On Fast and Accurate Detection of Unauthorized Wireless Access Points Using Clock Skews PB - IEEE Computer Society VL - 99 KW - 80211 KW - clock_skew KW - crawdad KW - rogue-ap KW - timing KW - uw_sigcomm2004 KW - wireless-security AU - Jana, Suman AU - Kasera, Sneha PY - 5555/// UR - http://dx.doi.org/10.1109/TMC.2009.145 ER -