Configuration hopping: A secure communication protocol without explicit key exchange

Abstract

By changing one or more physical layer parameters (such as spreading code, symbol duration, symbol constellation, center frequency, modulation method, transmission power, etc.) in an agreed upon manner between two communication parties, we are able to realize communication that is hard to detect, identify, and decode. We present a formal link layer protocol for secure communication based on this idea that, along with the use of channel reciprocity, notably eschews the use of cryptographic keys. We prove the security properties of the protocol in the Canetti-Krawczyk framework and study the feasibility of changing several physical layer parameters at the link packet level in Software Defined Radios.