Enhancing Location Privacy in Wireless LAN Through Disposable Interface Identifiers: A Quantitative Analysis

• DOI: 10.1007/s11036-005-6425-1
• Publication Date: 2005-04-06T14:43:01Z
• Authors: Marco Gruteser; Dirk Grunwald
• Keywords: Unique identifier; MAC address; Interface (matter)

The recent proliferation of wireless local area networks (WLAN) has introduced new location privacy risks. An adversary controlling several access points could triangulate a client's position. In addition, interface identifiers uniquely identify each client, allowing tracking of location over time. We enhance location privacy through frequent disposal of a client's interface identifier. The described system curbs the adversary's ability to continuously track a client's position. Design challenges include selecting new interface identifiers, detecting address collisions at the MAC layer, and timing identifier switches to balance network disruptions against privacy protection. Using a modified authentication protocol, network operators can still control access to their network. An analysis of a public WLAN usage trace shows that disposing addresses before reassociation already yields significant privacy improvements.