An Authentication Protocol using Ultrasonic Ranging


This report presents a method for establishing and securing spontaneousinteractions on the basis of spatial references which are obtainedby accurate sensing of relative device positions. Utilising the Relateultrasonic sensing system, we construct an interlocked protocol usingradio frequency messages and ultrasonic pulses for verifying thattwo devices share a secret. This verification is necessary to preventman-in-the-middle attacks on standard Diffie-Hellman key agreement.