A Secure Key Pre-distribution Scheme for Wireless Sensor Networks

Key management in wireless sensor networks is a challenging problem because asymmetric key cryptosystems are unsuitable in resource constrained sensor nodes, and also because sensor nodes could be physically compromised by adversaries. Motivated by a key agreement scheme proposed by Leighton and Micali (LM-KDS) [7], we present a secure key pre-distribution scheme, called Random LM-KDS (R-LM-KDS), which combines LM-KDS and probabilistic approaches. Using LM-KDS as its building block, R-LM-KDS randomly distributes a small number of key servers among sensor nodes. If any pair of nodes cannot establish session key using their preloaded key materials, they may get key materials from a key server in its vicinity, which contains a large number of public key materials needed by nodes to establish session keys between them. R-LM-KDS preserves nice properties of LM-KDS yet takes advantage of flexibility of probabilistic approaches to yield greatly improved resilience against node capture attacks by trading off increased network communication overhead and insecure storage complexity. We also present an in depth analysis of our scheme in terms of its performance and associated overhead.