Quantum Key Distribution for Secure Encryption in Underwater Networks

Security is a crucial aspect of underwater acoustic networks, that are often used in mission critical scenarios, such as coastal surveillance, rapid environmental assessment and mine countermeasure applications. The broadcast nature of the acoustic channel makes it vulnerable to a variety of attacks, such as spoofing, men-in-the-middle and jamming. Moreover, the lack of a standardized key distribution system makes data confidentiality challenging. In this paper we investigate the use of quantum key distribution (QKD) in underwater networks, in order to ensure confidentiality and integrity of the communication. While in the terrestrial domain the use of the one-time-pad protocol (requiring the key length to be equal to the message length) is limited by the low rate of the QKD rate compared to the bitrate of radio transmissions, in the underwater domain the limited bandwidth of the acoustic channel makes QKD a valid approach also for the one-time-pad protocol. The system is tested both with an emulator and a field test: results show that QKD can be a valuable system to secure underwater acoustic networks.