Improving wireless privacy with an identifier-free link layer protocol

Ben Greenstein, Tadayoshi Kohno, Damon McCoy, Srinivasan Seshan, Jeffrey Pang, David Wetherall

    Research output: Chapter in Book/Report/Conference proceedingConference contribution

    Abstract

    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).

    Original languageEnglish (US)
    Title of host publicationMobiSys'08 - Proceedings of the 6th International Conference on Mobile Systems, Applications, and Services
    Pages40-53
    Number of pages14
    DOIs
    StatePublished - 2008
    Event6th International Conference on Mobile Systems, Applications, and Services - Breckenridge, CO, United States
    Duration: Jun 17 2008Jun 20 2008

    Other

    Other6th International Conference on Mobile Systems, Applications, and Services
    CountryUnited States
    CityBreckenridge, CO
    Period6/17/086/20/08

    Fingerprint

    Cryptography
    Telecommunication links
    Table lookup
    Phase shift keying
    Throughput
    Experiments

    Keywords

    • Anonymity
    • Privacy
    • Wireless. 802.11

    ASJC Scopus subject areas

    • Computer Networks and Communications
    • Computer Science Applications

    Cite this

    Greenstein, B., Kohno, T., McCoy, D., Seshan, S., Pang, J., & Wetherall, D. (2008). Improving wireless privacy with an identifier-free link layer protocol. In MobiSys'08 - Proceedings of the 6th International Conference on Mobile Systems, Applications, and Services (pp. 40-53) https://doi.org/10.1145/1378600.1378607

    Improving wireless privacy with an identifier-free link layer protocol. / Greenstein, Ben; Kohno, Tadayoshi; McCoy, Damon; Seshan, Srinivasan; Pang, Jeffrey; Wetherall, David.

    MobiSys'08 - Proceedings of the 6th International Conference on Mobile Systems, Applications, and Services. 2008. p. 40-53.

    Research output: Chapter in Book/Report/Conference proceedingConference contribution

    Greenstein, B, Kohno, T, McCoy, D, Seshan, S, Pang, J & Wetherall, D 2008, Improving wireless privacy with an identifier-free link layer protocol. in MobiSys'08 - Proceedings of the 6th International Conference on Mobile Systems, Applications, and Services. pp. 40-53, 6th International Conference on Mobile Systems, Applications, and Services, Breckenridge, CO, United States, 6/17/08. https://doi.org/10.1145/1378600.1378607
    Greenstein B, Kohno T, McCoy D, Seshan S, Pang J, Wetherall D. Improving wireless privacy with an identifier-free link layer protocol. In MobiSys'08 - Proceedings of the 6th International Conference on Mobile Systems, Applications, and Services. 2008. p. 40-53 https://doi.org/10.1145/1378600.1378607
    Greenstein, Ben ; Kohno, Tadayoshi ; McCoy, Damon ; Seshan, Srinivasan ; Pang, Jeffrey ; Wetherall, David. / Improving wireless privacy with an identifier-free link layer protocol. MobiSys'08 - Proceedings of the 6th International Conference on Mobile Systems, Applications, and Services. 2008. pp. 40-53
    @inproceedings{2164a30961634ca687e6d0348b0a600e,
    title = "Improving wireless privacy with an identifier-free link layer protocol",
    abstract = "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).",
    keywords = "Anonymity, Privacy, Wireless. 802.11",
    author = "Ben Greenstein and Tadayoshi Kohno and Damon McCoy and Srinivasan Seshan and Jeffrey Pang and David Wetherall",
    year = "2008",
    doi = "10.1145/1378600.1378607",
    language = "English (US)",
    isbn = "9781605581392",
    pages = "40--53",
    booktitle = "MobiSys'08 - Proceedings of the 6th International Conference on Mobile Systems, Applications, and Services",

    }

    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

    SN - 9781605581392

    SP - 40

    EP - 53

    BT - MobiSys'08 - Proceedings of the 6th International Conference on Mobile Systems, Applications, and Services

    ER -