Key splitting: making random key distribution schemes resistant against node capture



A large number of random key pre-distribution (RKD) schemes have been proposed in the literature to secure wireless sensor network applications, relying on symmetric key cryptography. However, sensor nodes are exposed to physical compromise by adversaries, who target the symmetric keys stored at each node. With the stolen keys in their possession, the adversaries are then able to compromise communication links between benign nodes. Here, the big challenge arises: how to increase resilience of RKD schemes for wireless sensor networks to node capture, while maintaining the flexibility and low-cost features of RKD? We propose the idea of key splitting to address this problem, without the need of any special-purpose hardware. Our key splitting scheme neither increases per-node storage nor introduces additional computation and communication overheads. Nevertheless, it can achieve better connectivity. More importantly, it significantly increases resilience to node compromise, when the adversary does not have overwhelming computational power. Copyright © 2014 John Wiley & Sons, Ltd.