Enhancing underwater sensor network security using QKD-enabled acoustic–optical hybrid communication

Underwater Wireless Sensor Networks (UWSNs) function as essential systems which support naval defence operations, environmental monitoring, offshore industrial work and sea-depth exploration activities. These networks experience major performance problems along with security-related issues. The communication distance of acoustic links extends far, but their data transfer speed remains slow, while they experience high latency and get disrupted by noise, multipath fading and interference. The dual nature of underwater communication systems creates a permanent conflict between achieving fast data transfer rates and extending network coverage. The current technical barriers in UWSNs become more challenging because standard encryption methods fail to protect against quantum computer attacks; which enable eavesdropping and man-in-the-middle attacks. The Quantum-Assisted Keying-Underwater Wireless Sensor Network (QuAKey-UWSN) system uses Quantum Key Distribution (QKD) with adaptive acoustic-optical communication to create a new hybrid framework that addresses current network limitations. QKD is used to develop unbreakable encryption through physical laws, which detect bugging, overhearing, secret spying attacks, while the versatile fusion planner chooses between acoustic and optical channels for instant quantum key distribution and passing data exchange, depending on the acoustic channels for long range communication. The system uses MATLAB, NS-3 and Qiskit for simulation testing to demonstrate its operational success. The system produces secure keys at more than 3.5 kbps while maintaining 99% packet delivery ratio and 10.5 ms average latency. In this analysis QuAKey-UWSN has shown effective performance with strong robustness and wide-ranging capabilities, making it suitable for underwater operations that require dependable and secure communication systems.