Physical Layer Node Authentication in Underwater Acoustic Sensor Networks Using Time-Reversal

Underwater acoustic sensor networks (UASNs) have played a vital role in many security-sensitive applications like offshore oil exploration, tsunami forecast, and tactical surveillance. Due to the complex marine environment and harsh acoustic channel, UASNs face severe security challenges and attacks. Exploiting the multi-path energy from the richly scattering underwater environment, the time-reversal (TR) process can form the resonating strength based on the channel impulse response (CIR). Inspired by the natural link signature resulting from the spatial dependency of acoustic links, an authentication scheme using the maximum TR resonating strength is proposed, with the aim of effectively detecting the spoofing attacks in UASNs. To accommodate the time-varying nature of the underwater acoustic link, a database correlation method is exploited to capture the link CIR pattern over time for each link, which efficiently improves the accuracy of the authentication scheme using the TR process. Hence, the proposed algorithm enables each node to make the authentication decision based on maximum time-reversal resonating strength (MTRRS) locally with little overhead. It was evaluated by the probabilities of authentication, attack detection, and false alarm through extensive simulations. Finally, this MTRRS-based authentication was verified using the sea trial CIR data.