Wireless Physical-Layer Authentication for the Internet of Things

Authentication of messages in an Internet of Things (IoT) is a key security feature that may involve heavy signaling and protocol procedures, not suitable for small devices with very limited computational capabilities and energy availability. In this chapter we address the problem of message authentication in an IoT context, by using physical-layer approaches. We propose a solution based on the use of trusted anchor nodes that estimate the channel from the transmitting node and report them to a concentrator node, which takes a decision on the message authenticity. Assuming that the anchor nodes have a limited energy availability, we analyze the lifespan of the authenticating network and propose both centralized and distributed approaches to determine which anchor nodes report the information to the concentrator. The authenticating network overhead is also discussed and a tradeoff between energy efficiency and signaling traffic is found.