Trustworthy Wireless

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Trustworthy Wireless. Jeffrey Pang, Srinivasan Seshan Ben Greenstein, Ramakrishna Gummadi, Tadayoshi Kohno, David Wetherall. Why You Should Worry About Wireless Privacy. Ubiquity of 802.11 Networks. (typically < 100m). Cheap Radios, Monitoring Software. Ubiquity of 802.11 Devices. - PowerPoint PPT Presentation

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  • Trustworthy Wireless Yes: MAC address = unique identifier Previously proposed solution: Pseudonyms (change MAC address each session) Pseudonyms are not enough! Implicit identifiers remain (exposed characteristics of network traffic)Can Your Wireless Traffic Reveal Where Youve Been?What Your Wireless Traffic Says About You(typically < 100m)Cheap Radios,MonitoringSoftwareUbiquity of802.11Networks802.11 Access Points in ChicagotcpdumpCan Your Wireless Traffic Identify You?Implicit Identifier ExamplesNetwork destinations: web bookmarks, your email server, VPN server, etc.Wireless Network Names: networks youve visited before (e.g., your home)802.11 Protocol Fields: wireless card implementation and configurationPacket Sizes: size of broadcast packets (NetBIOS, MS Office, mDNS, etc.)Implicit Identifier AccuracyTypical HotspotBest PracticesExample: 1 in 4 users identified >50% of the time with 0.1% false positivesVisible even with WPA,WEP encryption! Yes: Laptops probe for network names youve connected to before Network names (SSIDs) are often identifying (e.g., CMU, IR Guest, Bob Home) Fundamental Problem: device discovery and pairing is not privateExample of Where Youve Beendjw = David J. Wetheralls Home Network?(1) Collect some wireless data Anonymized SIGCOMM 2004 802.11 Trace(2) Lookup suspect SSID in a war driving database(3) Find suspects home using Google Maps!Jeffrey Pang, Srinivasan Seshan Ben Greenstein, Ramakrishna Gummadi, Tadayoshi Kohno, David WetherallUbiquity of802.11DevicesWhy You Should Worry About Wireless Privacyhotspothomecorporation