SIMPLE AND FLEXIBLE RANDOM KEY PRE - DISTRIBUTION SCHEMES FOR WIRELESS SENSOR NETWORKS USING DEPLOYMENT KNOWLEDGE by S İ

Sensor nodes are tiny, low-power and battery constrained electromechanical devices that are usually deployed for sensing some type of data in different types of areas. Because of their memory and computational restrictions, public key cryptography (PKC) systems are not suited for sensor nodes to provide security. Instead, private key cryptography is preferred to be used with sensor networks and there has been considerable work in this area, but there still exist problems with private key cryptography because of memory restrictions of sensor nodes. Number of keys that can be deployed into a sensor node is determined by the available memory of that node which is limited even private key cryptographic techniques are applied. So, new key distribution mechanisms are required to decrease number of pairwise keys that are deployed into a sensor node. Random key pre-distribution mechanisms have been proposed to overcome memory restrictions of sensor nodes. These mechanisms are widely accepted for sensor network security. Simply, these schemes try do decrease the number of keys to be deployed in each sensor node in a sensor network and provide reasonable security for the sensor network. Random key pre-distribution schemes proposed until now have some deficiencies. Some of these schemes are too complicated and too difficult to be applied. Schemes that seem deployable involve unrealistic assumptions when real world scenarios are considered. In this thesis, we propose random key pre-distribution mechanisms that are simple and easily deployable. In this thesis, we first developed a generalized random key pre-distribution scheme. Then we proposed three random key pre-distribution mechanisms based on this generalized scheme and we provided their simulation results and their comparison to well-known random key pre-distribution schemes in the literature. Our generalized scheme allows different systems to be derived according to deployment needs. It offers simple, easily deployable distribution mechanisms and provides reasonable connectivity and resiliency with respect to its simplicity. To my precious vii ACKNOWLEDGEMENTS