iPAK: An In-Situ Pairwise Key Bootstrapping Scheme for Wireless Sensor Networks

Wireless sensor networks (WSNs) are characterized by resource constraints and large scalability. Many applications of WSNs require secure communication, a crucial component especially in hostile environments. However, the low computational capability and small storage budget within sensors render many popular public-key-based cryptographic systems impractical. Symmetric key cryptography, on the other hand, is attractive due to its efficiency. Nevertheless, establishing a shared key for communicating parties is a challenging problem. In this paper, we propose and analyze an in situ PAirwise Key bootstrapping scheme (iPAK) for large-scale WSNs. Our theoretical analysis and simulation study demonstrate that iPAK can achieve a high key-sharing probability between neighboring sensors and a strong resilience against node-capture attacks at the cost of low storage overhead.