Experimental study of secret key generation in underwater acoustic channels

Preestablished secret keys are often used to encrypt and decrypt data in communication systems, including underwater acoustic (UWA) systems. However, once the keys are compromised, the communication is not secure. It is desirable to establish shared secrets in the field. One method is to generate secret keys dynamically using correlated channel measurements, which relies on the randomness in the environment and does not require the secrecy of information exchanged during the process. We explore this concept in UWA channels and lake tests show that secret keys can be dynamically generated based on the channel frequency responses.