On Secure Key Management in Mobile Ad Hoc Networks

It is widely believed that although being more complex, a probabilistic key predistribution scheme is much more resilient against node capture than a deterministic one in lightweight wireless ad hoc networks. Backed up by the surprisingly large successful attack probabilities computed in this paper, we show that the probabilistic approaches have only limited performance advantages over deterministic approaches. We first consider a static network scenario as originally considered in the seminal paper by Eschenauer and Gligor [1], where any node capture happens after the establishment of all pairwise links, and show that the deterministic approach can achieve a performance as good as the probabilistic one. Whereas in a mobile network, the probabilistic key management as described in [1] can lead to a successful attack probability (SAP) of one order of magnitude larger than the one in a static network due to node fabrication attacks. Finally, we propose two low-cost secure-architecture-based techniques to improve the security against such attacks. Our new architectures, specifically targeted at the sensornode platform, protect long-term keys using a root of trust embedded in the hardware System-on-a-Chip (SoC). This prevents an adversary from extracting these protected long-term keys from a captured node to fabricate new nodes. The extensive simulation results show that the proposed architecture can significantly decrease the SAP and increase the security level of key management for mobile ad hoc networks.