Adding artificial noise for code rate matching in continuous-variable quantum key distribution

Abstract

The reconciliation step of continuous-variable quantum key distribution protocols usually involves forward error correction codes. Matching the code rate and the signal-to-noise ratio (SNR) of the quantum channel is required to achieve the high reconciliation efficiencies that are crucial for long distance links. Puncturing and shortening is a way to adapt the code rate to the SNR at the cost of a slightly reduced reconciliation efficiencies. Instead of adapting the code rate to the SNR, we propose to add a controlled amount of artificial noise to the measured data, so that the resulting SNR could be reduced to match the given code rate. We show that our method can compete with puncturing and shortening and even outperform it in high-loss, high-excess noise scenarios.

References in corpus (7)

• Continuous variable quantum cryptography using coherent states
• An information-theoretic security proof for QKD protocols
• Distributing Secret Keys with Quantum Continuous Variables: Principle, Security and Implementations
• Long Distance Continuous-Variable Quantum Key Distribution with a Gaussian Modulation
• Multidimensional reconciliation for continuous-variable quantum key distribution
• Reconciliation of a Quantum-Distributed Gaussian Key
• Rate Compatible Protocol for Information Reconciliation: An application to QKD