An Evaluation of Location Privacy in Wireless Sensor Networks

Due to the open nature of a sensor network, it is relatively easy for an adversary to eavesdrop andtrace packet movement in the network in order to capture the receiver physically. After studying theadversary’s behavior patterns, we present countermeasures to this problem. We propose a location-privacyrouting protocol (LPR) that is easy to implement and provides path diversity. Combining with fake packetinjection, LPR is able to minimize the traffic direction information that an adversary can retrieve fromeavesdropping. By making the directions of both incoming and outgoing traffic at a sensor node uniformlydistributed, the new defense system makes it very hard for an adversary to perform analysis on locallygathered information and infer the direction to which the receiver locates. We evaluate our defense systembased on three criteria: delivery time, privacy protection strength, and energy cost. The simulation resultsshow that LPR with fake packet injection is capable of providing strong protection for the receiver’s locationprivacy. Under similar energy cost, the safe time of the receiver provided by LPR is much longer than othermethods, including Phantom routing [1] and DEFP [2]. The performance of our system can be tunedthrough a couple of parameters that determine the tradeoff between energy cost and the strength of locationprivacyprotection.