Countermeasures Against Traffic Analysis Attacks in Wireless Sensor Networks

Wireless sensor networks are highly vulnerable to the failure of base stations. An adversary can render a wireless sensor network useless by launching remote, softwarebased attacks or physical attacks on the base stations. This paper addresses the problem of defending a base station against physical attacks by concealing the geographic location of a base station. Typical packet traffic in a sensor network reveals pronounced patterns that allow an adversary analyzing packet traffic to deduce the location of a base station. The paper investigates several countermeasures against traffic analysis techniques aimed at disguising the location of a base station. First, a degree of randomness is introduced in the multi-hop path a packet takes from a sensor node to a base station. Second, random fake paths are introduced to confuse an adversary from tracking a packet as it moves towards a base station. Finally, multiple, random areas of high communication activity are created to deceive an adversary as to the true location of the base station. The paper evaluates these techniques analytically and via simulation using three evaluation criteria: total entropy of the network, total energy consumed, and the ability to guard against heuristic-based techniques to locate a base station.