TY - GEN
T1 - Improving wireless privacy with an identifier-free link layer protocol
AU - Greenstein, Ben
AU - Kohno, Tadayoshi
AU - McCoy, Damon
AU - Seshan, Srinivasan
AU - Pang, Jeffrey
AU - Wetherall, David
PY - 2008
Y1 - 2008
N2 - We present the design and evaluation of an 802.11-like wireless link layer protocol that obfuscates all transmitted bits to increase privacy. This includes explicit identifiers such as MAC addresses, the contents of management messages, and other protocol fields that the existing 802.11 protocol relies on to be sent in the clear. By obscuring these fields, we greatly increase the difficulty of identifying or profiling users from their transmissions in ways that are otherwise straightforward. Our design, called SlyFi, is nearly as efficient as existing schemes such as WPA for discovery, link setup, and data delivery despite its heightened protections; transmission requires only symmetric key encryption and reception requires a table lookup followed by symmetric key decryption. Experiments using our implementation on Atheros 802.11 drivers show that SlyFi can discover and associate with networks faster than 802.11 using WPA-PSK. The overhead SlyFi introduces in packet delivery is only slightly higher than that added by WPA-C CMP encryption (10% vs. 3% decrease in throughput).
AB - We present the design and evaluation of an 802.11-like wireless link layer protocol that obfuscates all transmitted bits to increase privacy. This includes explicit identifiers such as MAC addresses, the contents of management messages, and other protocol fields that the existing 802.11 protocol relies on to be sent in the clear. By obscuring these fields, we greatly increase the difficulty of identifying or profiling users from their transmissions in ways that are otherwise straightforward. Our design, called SlyFi, is nearly as efficient as existing schemes such as WPA for discovery, link setup, and data delivery despite its heightened protections; transmission requires only symmetric key encryption and reception requires a table lookup followed by symmetric key decryption. Experiments using our implementation on Atheros 802.11 drivers show that SlyFi can discover and associate with networks faster than 802.11 using WPA-PSK. The overhead SlyFi introduces in packet delivery is only slightly higher than that added by WPA-C CMP encryption (10% vs. 3% decrease in throughput).
KW - Anonymity
KW - Privacy
KW - Wireless. 802.11
UR - http://www.scopus.com/inward/record.url?scp=57349141867&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=57349141867&partnerID=8YFLogxK
U2 - 10.1145/1378600.1378607
DO - 10.1145/1378600.1378607
M3 - Conference contribution
AN - SCOPUS:57349141867
SN - 9781605581392
T3 - MobiSys'08 - Proceedings of the 6th International Conference on Mobile Systems, Applications, and Services
SP - 40
EP - 53
BT - MobiSys'08 - Proceedings of the 6th International Conference on Mobile Systems, Applications, and Services
T2 - 6th International Conference on Mobile Systems, Applications, and Services
Y2 - 17 June 2008 through 20 June 2008
ER -