EXTENDED SECURITY ASSESSMENT MODEL FOR COOPERATIVE ESTABLISHMENT OF SECURE CHANNELS IN WIRELESS SENSOR NETWORKS

Abstract

The development of wireless sensor networks and their integration into the Internet of Things (IoT) infrastructure necessitate the improvement of mechanisms for establishing secure channels between resource-constrained components. One approach to addressing this problem is cooperative key establishment, in which a secure channel between two sensor nodes is established with the involvement of a set of intermediate cooperating sensors. The classical ECCE protocol increases the probability of secure channel establishment and improves resilience against node compromise; however, its basic analytical model is primarily focused on the parameters of random key predistribution and the number of cooperating devices.

This paper proposes an extended probabilistic model for assessing the security of a cooperative channel. In addition to the parameters of the global key pool, key-ring size, and number of cooperating sensors, the model takes into account the number of compromised nodes and the probability of wireless link availability. An effective secure connectivity metric is introduced, simultaneously characterizing the availability of shared keying material, the absence of its compromise, and the physical availability of the wireless communication link. Based on this metric, an analytical estimate of the probability of secure channel establishment is derived for both direct and two-hop cooperative scenarios.

The obtained results demonstrate the applicability of the proposed approach to analyzing the trade-off among key-ring size, the number of cooperating nodes, resilience to node compromise, and wireless channel quality.