Attacks on Sensing in Hostile Wireless Sensor-Actuator Environments

Wireless Sensor Networks (WSNs) deployed in hostile environments are susceptible to various attacks directed at their data. In this work we focus on an emerging and largely unexplored issue arising from the presence of actuator (or actor) nodes in the form of Wireless Sensor Actuator Networks (WSANs). Specifically, we consider the case where hostile WSAN nodes belonging to a foreign network directly perturb the readings of WSN nodes during sensing. The attack is modeled as affecting the decision that a WSN node reports about the presence or absence of a phenomenon to its cluster head. To assess the potential loss of sensing fidelity due to the opposing network, we employ a game theoretic analysis. We focus on determining the probability that the WSN cluster head becomes alerted to such an attack given some statistical information about the phenomenon. Our results show that an actuation attack may go unnoticed even if such an attack is not coordinated among the hostile WSAN nodes. Importantly, the number of WSN nodes in a cluster affects the probability of WSAN attack success. For clusters consisting of only a few nodes, the hostile WSAN may achieve a stealthy attack with a wider range of attack parameters. We also determine that natural phenomena with certain characteristics are more susceptible to the attack and require further sensing-verification mechanisms.