Advanced quantum key distribution protocol for mitigating quantum-based vulnerabilities in blockchain applications

Abstract Since blockchain platforms still depend on classical cryptographic protocols, they become more and more vulnerable to the rapid advancement of quantum computing. However, the emergence of quantum attacks has placed the need to develop Quantum Key Distribution (QKD) protocols that can preserve security while eliminating the limitations of quantum information systems, such as noise and error mitigation. To address these needs, this study proposes a novel Hybrid Rainbow-Kyber QKD (HRK-QKD) Protocol, which uses the strength of multivariate quadratic equations in Rainbow to mask the classical keys and the efficiency of lattice-based encryption in Kyber for key encryption. An entanglement-assisted dynamic key synthesis protocol that combines matrix-based quantum noise filtering, lattice-based multi-dimensional transformations and adaptive private key rotations is utilized. The proposed methods provide real-time mitigation of quantum noise and minimal performance overhead for key generation. HRK-QKD achieves the highest scalability ratio ( $Sc=2.7$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mi>S</mml:mi> <mml:mi>c</mml:mi> <mml:mo>=</mml:mo> <mml:mn>2.7</mml:mn> </mml:math> ), the best noise resilience (0.90-0.99), and the highest quantum security measure ( $Q_{S}=0.064881$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msub> <mml:mi>Q</mml:mi> <mml:mi>S</mml:mi> </mml:msub> <mml:mo>=</mml:mo> <mml:mn>0.064881</mml:mn> </mml:math> ) with minimal information leakage probability (0.00001). This advancement also means blockchain remains a resilient technology against quantum threats, with an economical, scalable, and high-accuracy solution for next-generation secure communication systems.