EAQKD: Entanglement-Based Authenticated Quantum Key Distribution

TL;DR

EAQKD introduces a new entanglement-based protocol that combines quantum entanglement with information-theoretic authentication, enabling secure quantum key distribution over long distances with practical performance and robustness.

Contribution

This paper presents EAQKD, a novel protocol integrating entanglement distribution with authentication, and provides a comprehensive simulation-based performance analysis under realistic conditions.

Findings

Quantum bit error rates stay below 11% security threshold up to 200 km

Secure key rates of 1.12 x 10^5 bits/s at short distances

EAQKD can extend secure communication beyond 500 km with quantum repeaters

Abstract

The promise of unconditional security in the Quantum Key Distribution (QKD) depends on the availability of an authenticated classical channel. However, practical implementations often overlook this requirement or rely on computational assumptions that compromise long-term security. To overcome these challenges, this paper presents Entanglement-Based Authenticated Quantum Key Distribution (EAQKD), a novel protocol that addresses critical security and practical limitations in quantum cryptographic key exchange. Our approach integrates quantum entanglement distribution with information-theoretic authentication. We evaluate EAQKD's performance through a comprehensive discrete-event simulation framework modeled on realistic channel characteristics and experimental device parameters. Our modeling incorporates parameters from practical quantum optics setups, including SPDC entanglement sources, superconducting nanowire detectors, and fiber channel imperfections. Our results show quantum bit error rates consistently below the 11% security threshold (ranging from 1.86% at 10 km to 9.27% at 200 km), with secure key rates achieving $1.12 \times 10^5$ bits/s at short distances and maintaining practical rates of 9.8 bits/s at 200 km. When integrated with quantum repeater architectures, our analysis projects that EAQKD can extend secure communication beyond 500 km while providing information-theoretic security guarantees. Comparative analysis against the BB84, E91, and Twin-Field QKD protocols demonstrates EAQKD's superior balance of security, practical performance, and implementation robustness. This work advances quantum cryptography by providing a rigorously analyzed engineering reference for secure key distribution in future quantum communication networks.