Quantum Meets Statistical-Physical Secrecy: A Novel Hybrid Key Distribution Architecture

2026-05-14

AI Summary

This work addresses the efficiency bottleneck and information leakage risks inherent in traditional quantum key distribution (QKD), which relies on public basis reconciliation and sifting. The authors propose a parallel hybrid architecture integrating QKD with the Kirchhoff-law–Johnson-noise (KLJN) key exchange, wherein the KLJN link securely handles basis information and assists in raw key generation without requiring public communication. Building on this framework, three novel KLJN-assisted QKD protocols are devised, enabling, for the first time, basis-derived key extraction without public basis disclosure and raw key generation under ideal KLJN assumptions. By combining BB84 optical quantum channels with wired KLJN circuits and accounting for channel loss, bandwidth, and synchronization constraints, the study establishes an analytical model for normalized key rate and throughput, demonstrating significantly enhanced key generation efficiency and system throughput in short-distance scenarios such as metropolitan networks and data center interconnects.

Abstract

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.

Problem

• quantum key distribution
• KLJN
• key rate
• secure communication
• hybrid architecture

Innovation

• hybrid key distribution
• quantum key distribution (QKD)
• KLJN
• statistical-physical secrecy
• basis reconciliation