Countering passive cyber attacks against sink nodes in tactical sensor networks using reactive route obfuscation

Abstract Tactical wireless sensor networks (WSNs) are deployed by military communities for mission centric operations. The sink node is a sensor network's single point of failure and is a high priority target for an attacker. This paper focuses on the mitigation of sink node vulnerability in a tactical WSN using reactive route obfuscation. We study the issue of protecting the sink node through a common technique known as k -anonymity. To achieve k -anonymity, we use a specific routing protocol designed to work within the constraints of WSN communication protocols, specifically IEEE 802.15.4 and 6LoWPAN. We use the IETF's Lightweight Ad hoc On-Demand Next Generation (LOADng) reactive routing protocol to achieve anonymity. We modify the LOADng routing protocol such that routes to the sink node are obfuscated through the use of pseudo-sink nodes. We simulate the modified LOADng protocol using a custom-designed simulator in MATLAB. We demonstrate the effectiveness of our protocol by quantifying the anonymity level achieved. We also study the effectiveness of our modified LOADng protocol to mitigate a passive cyber attack using traffic analysis that identifies and disables the sink node. Lastly, the network performance of the modified LOADng algorithm is quantified in terms of power usage, latency and path length.