Quantum Meets Statistical-Physical Secrecy: A Novel Hybrid Key Distribution Architecture
For quantum key distribution networks, this hybrid approach offers incremental improvements in key rate and efficiency by integrating a parallel KLJN link for basis handling.
The paper proposes a hybrid key distribution architecture combining QKD and KLJN statistical-physical key exchange, introducing three protocols that eliminate public basis disclosure and improve key generation efficiency. Numerical results show throughput improvements in short-haul networks like MANs and data center interconnects.
This letter proposes a novel hybrid key distribution architecture that jointly exploits quantum key distribution (QKD) and Kirchhoff-law-Johnson-noise (KLJN) statistical-physical key exchange. In the proposed system, an optical BB84-type QKD link operates in coordination with a parallel wired KLJN link, which is used for secure basis handling and, in selected protocols, additional raw key generation. Three novel KLJN-assisted QKD protocols are introduced to eliminate public basis disclosure messages and bit sifting, extract basis-derived key bits, or generate raw key bits under ideal KLJN assumptions. Analytical expressions for the normalized key rate and absolute throughput are derived by accounting for optical channel penalties, KLJN bandwidth constraints, and synchronization bottlenecks. Numerical results show that the proposed hybrid architecture can improve key generation efficiency and throughput in short-haul infrastructures, including metropolitan area networks (MANs) and data center interconnects.