Appending Information Reconciliation for Quantum Key Distribution

TL;DR

This paper introduces an appending information reconciliation scheme based on polar codes that enhances efficiency and reduces failure probability in quantum key distribution systems, bringing practical performance closer to theoretical limits.

Contribution

The paper proposes a novel AIR scheme using polar codes that achieves near-Shannon limit efficiency with ultra-low failure probability, especially for small block sizes.

Findings

Efficiency close to Shannon limit (1.046 at 1 Gb block size)

Failure probability around 1E-8

Improved performance over existing polar codes-based IR schemes

Abstract

Information reconciliation (IR), which corrects the errors in the sifted keys, directly determines the secure key rate and the link distance of quantum key distribution (QKD) systems. In this article, we propose an appending information reconciliation (AIR) scheme based on polar codes, which achieves high efficiency and ultra-low failure probability simultaneously, by gradually disclosing the bit values of the polarized channels with high error probability. The experimental results show that the efficiency of the proposed AIR scheme is closer to the Shannon limit, compared with the state-of-the-art implemented polar codes-based IR schemes, with the overall failure probability around 1E-8, especially when performed with smaller block sizes. Moreover, the efficiency of the proposed AIR scheme is 1.046, when the block size is 1 Gb and the quantum bit error rate of 0.02. Therefore, the proposed AIR scheme can further eradicate the performance gap between theory and implementation for QKD systems.