{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,9,30]],"date-time":"2025-09-30T00:08:13Z","timestamp":1759190893214,"version":"3.44.0"},"reference-count":31,"publisher":"MDPI AG","issue":"10","license":[{"start":{"date-parts":[[2025,9,29]],"date-time":"2025-09-29T00:00:00Z","timestamp":1759104000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Key-Area Research and Development Program of Guangdong Province","award":["2018B030325002"],"award-info":[{"award-number":["2018B030325002"]}]}],"content-domain":{"domain":["www.mdpi.com"],"crossmark-restriction":true},"short-container-title":["Entropy"],"abstract":"<jats:p>Continuous-variable quantum key distribution faces significant challenges, including quantum channel instability, particularly fluctuations in the signal-to-noise ratio (SNR) and extremely low SNR scenarios. Furthermore, non-ideal polar codes, characterized by insufficient polarization in finite-length regimes, can lead to some sub-channels being neither completely noise-free nor fully noise-dominated. This phenomenon limits the error correction capability when such codes are applied to information reconciliation. To address these challenges, we propose a novel RC-LDPC-Polar code for the CV-QKD reconciliation algorithm. We combine the error resilience of LDPC codes with the efficiency advantages of polar coding. This scheme supports adaptive rate adjustment across varying SNR conditions. Our simulation experiments demonstrate that the RC-LDPC-Polar concatenated coding scheme achieves a lower error rate under varying SNR conditions. Meanwhile, the proposed scheme achieves a higher final key rate and a longer transmission distance.<\/jats:p>","DOI":"10.3390\/e27101025","type":"journal-article","created":{"date-parts":[[2025,9,29]],"date-time":"2025-09-29T10:49:34Z","timestamp":1759142974000},"page":"1025","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["RC-LDPC-Polar Codes for Information Reconciliation in Continuous-Variable Quantum Key Distribution"],"prefix":"10.3390","volume":"27","author":[{"given":"Fei","family":"Hua","sequence":"first","affiliation":[{"name":"Guangdong Provincial Key Laboratory of Nanophotonic Functional Materials and Devices, School of Optoelectronic Science and Engineering, South China Normal University, Guangzhou 510006, China"},{"name":"Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials, School of Optoelectronic Science and Engineering, South China Normal University, Guangzhou 510006, China"},{"name":"National Quantum Communication (Guangdong) Co., Ltd., Guangzhou 510700, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Kun","family":"Chen","sequence":"additional","affiliation":[{"name":"Guangdong Provincial Key Laboratory of Nanophotonic Functional Materials and Devices, School of Optoelectronic Science and Engineering, South China Normal University, Guangzhou 510006, China"},{"name":"Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials, School of Optoelectronic Science and Engineering, South China Normal University, Guangzhou 510006, China"},{"name":"National Quantum Communication (Guangdong) Co., Ltd., Guangzhou 510700, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0009-0001-3168-4869","authenticated-orcid":false,"given":"Wei","family":"Deng","sequence":"additional","affiliation":[{"name":"Guangdong Provincial Key Laboratory of Nanophotonic Functional Materials and Devices, School of Optoelectronic Science and Engineering, South China Normal University, Guangzhou 510006, China"},{"name":"Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials, School of Optoelectronic Science and Engineering, South China Normal University, Guangzhou 510006, China"},{"name":"National Quantum Communication (Guangdong) Co., Ltd., Guangzhou 510700, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Jing","family":"Cheng","sequence":"additional","affiliation":[{"name":"Guangdong Provincial Key Laboratory of Nanophotonic Functional Materials and Devices, School of Optoelectronic Science and Engineering, South China Normal University, Guangzhou 510006, China"},{"name":"Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials, School of Optoelectronic Science and Engineering, South China Normal University, Guangzhou 510006, China"},{"name":"National Quantum Communication (Guangdong) Co., Ltd., Guangzhou 510700, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Banghong","family":"Guo","sequence":"additional","affiliation":[{"name":"Guangdong Provincial Key Laboratory of Nanophotonic Functional Materials and Devices, School of Optoelectronic Science and Engineering, South China Normal University, Guangzhou 510006, China"},{"name":"Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials, School of Optoelectronic Science and Engineering, South China Normal University, Guangzhou 510006, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Huanwen","family":"Xie","sequence":"additional","affiliation":[{"name":"National Quantum Communication (Guangdong) Co., Ltd., Guangzhou 510700, China"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2025,9,29]]},"reference":[{"key":"ref_1","first-page":"109","article-title":"Cipher printing telegraph systems: For secret wire and radio telegraphic communications","volume":"45","author":"Vernam","year":"1926","journal-title":"J. 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