Key Management Schemes In Wireless Sensor Networks

Key management in wireless sensor networks is a challenging problem because asym-metric key cryptosystems are unsuitable for use in resource constrained sensor nodes, andalso because the nodes could be physically compromised by an adversary. Even though anumber of key distribution protocols have been proposed, none of them can simultaneouslyachieve good performance in terms of scalability in network size, key sharing probability be-tween neighboring sensors, memory overhead for keying information storage, and resilienceagainst node capture attacks. The techniques employed must depend upon the requirementsof target applications and resources of each individual sensor network.This dissertation makes several contributions. First, we introduce a deployment knowl-edge based key management scheme, domain-based key predistribution, which can achievea high key sharing probability with low storage overhead; Second, motivated by a key agree-ment scheme proposed by Leighton and Micali, we present a key establishment mechanismfor heterogeneous sensor networks. This scheme retains all the nice features of Leighton-Micali scheme, yet takes advantage of ?exibility of probabilistic approaches to yield improvedresilience against node capture attacks; Third, an asymmetric key predistribution schemeand its lower bounds are presented. Besides, its constructions and applications for sensornetworks are given; Fourth, we present key infection and evolution, a lightweight key manage-ment mechanism that is applicable even to smart dust sensor networks; Finally, to address thesecurity problems in Unattended wireless sensor networks, we present mAKPS, an asymmet-ric key predistribution scheme with mobile sinks, to facilitate key distribution and the privilegerestriction of mobile sinks. In addition, a scheme for sensors to protect their collected data ispresented.