A sensor network typically refers to a collection of sensor nodes equipped with sensing, communication and processing capabilities. It brings an opportunity to solve many difficult problems including real time monitoring, tracking, and controlling. While the applications of sensor networking become many and varied, security has always been one of the major concerns in real deployments. In this dissertation, we design physical primitives for secure communication in wireless sensor networks, and develop a wireless security framework to provide conventional security services.
We investigate the feasibility of achieving perfect secrecy and information authenticity without shared secrets via two physical primitives: (i) cooperative jamming primitive, where we introduce a secure coding problem in which not only the sender but also the receiver participates in the coding. In essence, the receiver’s role is to selectively jam the sender’s transmission at the level of bits, bytes, or packets. We then design a class of secure codes, called “dialog codes”, for diverse channel models and receiver models. (ii) spatial verification primitive, where we exploit the spatial signature induced by the radio communications of a node on its neighboring nodes, and design a spatial primitive that robustly and efficiently validates the authenticity of the source of messages. To address trust initialization, we propose a zero knowledge proof alternative that allows bootstrapping trust among individuals in a distributed way.
Based on the cooperative jamming primitive and spatial verification primitive, we develop a framework for wireless security that
provides conventional security services that include confidentiality, identity authentication, message authentication, integrity, sender non-repudiation, receiver non-repudiation and anonymity, not only for single-hop and end-to-end communications, but unicast and broadcast contexts as well. We show for the first time that a wide variety of security services are possible without any shared secrets and with only a small basis of physical primitives.