A pairwise key pre-distribution scheme for wireless sensor networks

TLDR

Wireless sensor networks require secure message encryption and authentication, yet resource constraints make key agreement difficult, traditional schemes such as Diffie‑Hellman unsuitable, and pre‑distributing keys for all node pairs infeasible due to memory limits. The authors propose a new key pre‑distribution scheme that substantially improves network resilience compared to existing approaches. The scheme’s pairwise key pre‑distribution design is analyzed for resilience and overhead, providing an in‑depth assessment of its performance. The scheme exhibits a threshold property: when fewer nodes are compromised than a threshold, the probability of affecting other nodes is near zero, thereby reducing the impact of small‑scale breaches and requiring attackers to compromise a large portion of the network.

Abstract

To achieve security in wireless sensor networks, it is important to be able to encrypt and authenticate messages sent among sensor nodes. Keys for encryption and authentication purposes must be agreed upon by communicating nodes. Due to resource constraints, achieving such key agreement in wireless sensor networks is non-trivial. Many key agreement schemes used in general networks, such as Diffie-Hellman and public-key based schemes, are not suitable for wireless sensor networks. Pre-distribution of secret keys for all pairs of nodes is not viable due to the large amount of memory used when the network size is large. To solve the key pre-distribution problem, two elegant key pre-distribution approaches have been proposed recently [11, 7].In this paper, we propose a new key pre-distribution scheme, which substantially improves the resilience of the network compared to the existing schemes. Our scheme exhibits a nice threshold property: when the number of compromised nodes is less than the threshold, the probability that any nodes other than these compromised nodes is affected is close to zero. This desirable property lowers the initial payoff of smaller scale network breaches to an adversary, and makes it necessary for the adversary to attack a significant proportion of the network. We also present an in depth analysis of our scheme in terms of network resilience and associated overhead.