Location corroboration using passive observations of IEEE 802.11 Access Points

Confidence in location is increasingly important in many applications. This is particularly true in augmented reality applications such as games. Users have an interest in being able to lie about their location. Location reporting methods implemented in existing services are weakly protected: it is often possible to lie in simple cases or to emit signals that deceive the more cautious systems. This paper proposes to observe the Wi-Fi routers near the user‘s location to strengthen confidence in the reported positions so as to complicate the task of an attacker. More particularly we are interested in the observation of the timestamps issued in the beacons of the access points. We show that this method is simple to implement, that it does not require any modification of existing hardware, that it is passive and that it significantly thwart the task of an attacker.