International Conference on Computing, Communication, Perception and Quantum Technology (CCPQT)

Enhanced Polynomial Interpolation Protocol for Secure and Efficient Quantum Key Distribution

Hong Yue Chen, Jiahua Zhang, Cong Wu

Published Oct 24, 2025• 0 citations

Abstract

Quantum key distribution (QKD) enables unconditional secure communication by exploiting the principles of quantum mechanics. However, existing reconciliation protocols face a trade-off between error correction efficiency and information leakage. To address this challenge, we propose an enhanced QKD reconciliation scheme based on polynomial interpolation. The protocol introduces a block-wise algebraic structure to unify error detection and correction, significantly reducing interactive rounds while maintaining high efficiency. A comprehensive information-theoretic leakage model is established, covering polynomial interpolation, verification, and iterative error localization. To further ensure unconditional security, a cascaded privacy amplification mechanism is integrated, combining two compression stages tailored to reconciliation leakage and quantum channel leakage, respectively. Moreover, an adaptive parameter optimization strategy dynamically adjusts block size and polynomial order according to the quantum bit error rate (QBER), achieving robustness under diverse channel conditions. Theoretical analysis and simulations demonstrate that the proposed scheme achieves a secure key rate of 65–72% at QBER < 3%, outperforming the classical CASCADE protocol by 8–12%, and maintains 30–50% efficiency under moderate error rates. Computational complexity analysis shows performance comparable to LDPC-based approaches while offering superior leakage control. These results confirm that the proposed protocol provides a balanced trade-off among efficiency, security, and implementation complexity, making it suitable for deployment in practical QKD systems.

DOI: 10.1109/ccpqt66408.2025.11383077

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