Securing Sensor Nodes Against Side Channel Attacks

Side channel attacks are non-invasive attacks in which adversaries gain confidential information by passively observing the target computing device. Sensor nodes are particularly vulnerable to side channel attacks due to the lack of protective physical shielding and their deployment in open environments. As sensor nodes are increasingly being deployed in safety critical applications such as power grid, volcano monitoring, and even military applications, protecting sensor nodes from side channel attacks is critical. However, side channel attacks on sensor nodes have not been investigated in previous work. In this paper, we present a taxonomy of side channel attacks on sensor nodes. For each type of the attacks, we provide guidelines and approaches to thwart the attack. We also propose a new technique, called process obfuscation, which can be used as a countermeasure for a variety of side channel attacks on sensor nodes. Furthermore, to demonstrate the feasibility of side channel attacks, we conducted electromagnetic leakage attacks, a type of side channel attack, on popular Tmote-sky sensor nodes using commercially available equipment.