On resilience and connectivity of secure wireless sensor networks under node capture attacks

TL;DR

This paper provides a formal analysis of the resilience and connectivity of the q-composite key predistribution scheme in wireless sensor networks, addressing real-world constraints and attack strategies to improve security against node capture and replication attacks.

Contribution

It offers a precise resilience analysis, optimal parameter derivation, and enhancements for the q-composite scheme, considering realistic conditions and attack models.

Findings

Derived scheme parameters for desired resiliency levels.

Achieved conditions for network connectivity under attacks.

Analyzed adversary strategies for node replication attacks.

Abstract

Despite much research on probabilistic key predistribution schemes for wireless sensor networks over the past decade, few formal analyses exist that define schemes' resilience to node-capture attacks precisely and under realistic conditions. In this paper, we analyze the resilience of the q-composite key predistribution scheme, which mitigates the node capture vulnerability of the Eschenauer-Gligor scheme in the neighbor discovery phase. We derive scheme parameters to have a desired level of resiliency, and obtain optimal parameters that defend against different adversaries as much as possible. We also show that this scheme can be easily enhanced to achieve the same "perfect resilience" property as in the random pairwise key predistribution for attacks launched after neighbor discovery. Despite considerable attention to this scheme, much prior work explicitly or implicitly uses an incorrect computation for the probability of link compromise under node-capture attacks and ignores real-world transmission constraints of sensor nodes. Moreover, we derive the critical network parameters to ensure connectivity in both the absence and presence of node-capture attacks. We also investigate node replication attacks by analyzing the adversary's optimal strategy.