Determining sink location through Zeroing-In attackers in wireless sensor networks

The viability and success of wireless sensor networks critically hinge on the ability of a small number of sinks to glean sensor data throughout the networks. Thus, the locations of sinks are critically important. In this paper, we examine the sink location privacy problem from both the attack and defense perspectives. First, we examine resource-constrained adversaries who can only eavesdrop the network at their vicinities. To determine the sink location, they can launch a Zeroing-In attack by leveraging the fact that several network metrics are 2-dimensional functions in the plane of the network, and their values minimize at the sink. Thus, determining the sink location is equivalent to finding the minima of those functions. We demonstrate that by obtaining the hop counts or the arrival time of a broadcast packet at a few spots in the network, the adversaries are able to determine the sink location with the accuracy of one radio range, which is sufficient to disable the sink by launching jamming attacks, for example. To cope with the Zeroing-In attacks, we present a directed-walk-based routing scheme and show that the defense strategy is effective in deceiving adversaries at little energy costs.