Proof of proximity with 802.11 wireless LAN

Authentication is crucial for every real-world wireless network to prevent unauthorized access. In many cases, incorporating the user´s position in a two-factor authentication strengthens the security of the network. Current positioning techniques are either manipulable, require extra hardware or violate the 802.11 standard. We propose three methods for authenticated positioning which work solely with commodity 802.11 hardware and are fully standards-compliant. After describing methods and backgrounds comprehensively we discuss security aspects by pointing out attack schemes and countermeasures, evaluate the implementability, and discuss the accuracy. While two of the methods show weaknesses which allow an attacker to reduce the accuracy of positioning, the 3rd proposed method is immune. The achievable accuracy is sufficient to restrict network access to company´s premises or large buildings.