Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

International Symposium on Problems of Redundancy in Information and Control Systems (REDUNDANCY)

Sampling Rate Optimization for LDPC-Based Information Reconciliation Protocol in QKD

Vladimir Morozov, Oleg Olegovich Evsutin, Nikita Yarygin

Published Nov 5, 2025• 1 citation
Publisher

Abstract

Quantum Key Distribution (QKD) is a promising field in modern cryptography where the security of key information is guaranteed by the laws of quantum mechanics. One of the key stages in QKD protocols is error estimation and reconciliation in the secret key. This procedure requires the transmission of a certain number of secret key bits over a public channel. Such transmission leads to disclosing these bits to a potential eavesdropper. The fraction of disclosed bits—the sampling rate-largely depends on the chosen approach for preliminary error estimation in the channel. This work is devoted to the optimization of the sampling rate for an LDPC code from the $\mathbf{5 G}$ standard. The results of our experiments show that for a QBER below 0.2 and key lengths of 264, 528, 792, and 1056 bits, it is necessary to disclose no more than $18 \%, 11 \%, 10 \%$, and $7 \%$ of the key bits for error estimation, respectively. Furthermore, the proposed algorithm allows for similar optimization for any information reconciliation protocols and actual quantum bit error rates.

DOI
10.1109/redundancy68069.2025.11301492

Related papers

Rate-adaptive reconciliation and its estimator for quantum bit error rate

Patcharapong Treeviriyanupab, Tharathorn Phromsa‐ard, Chun-Mei Zhang +10 more

The purpose of reconciliation, one of classical aspects of quantum key distribution (QKD) protocol, is to mitigate errors after the distribution of quantum information over a quantum channel. In this paper, a rate-adaptive method is proposed by means of a channel coding scheme where specific low-density parity-check (LDPC) codes are adapted in the Slepian-Wolf coding system. Puncturing and shortening techniques are adopted to optimize their coding rates with all possible cases of error in QKD. This successful method utilizes the knowledge of the quantum bit error rate (QBER) based on the maximum-likelihood estimator with respect to the syndrome information. Its benefit is that avoids wasting sample keys in the traditional channel estimation and thus increases the size of the final secret key. Evidently, simulation results confirm an improvement in the reconciliation efficiency with minimal interaction that suitable for high QKD throughput applications.

International Symposium on Communications and Information Technologies•Sep 1, 2014•12 citations

Adaptation of Error Correction Procedures to the Time-Bin Quantum Key Distribution Protocol Implementation

Vladimir Morozov, Mikhail S. Elezov, Oleg Olegovich Evsutin +1 more

Error correction is a crucial stage in quantum key distribution (QKD) protocols—a promising field of modern cryptography where the secrecy of the shared key information is guaranteed by the laws of quantum mechanics. Currently, there are many effective approaches to error correction in QKD. However, most of them, due to their generic nature, fail to leverage the specific features of particular protocol implementations. This work demonstrates that accounting for the hardware specifics of a QKD system implementing the time-bin protocol enables a significant increase in error correction performance. For the considered QKD system, we have experimentally obtained estimates of the Quantum Bit Error Rate (QBER) observed for each combination of bit and detector. The differences in the obtained estimates reveal that the quantum channel can be modeled as a non-uniform binary channel. Furthermore, based on computational experiments with a model of the quantum channel, it was established that adapting the error correction procedure to its properties can achieve up to a 2.7-fold reduction in the LDPC code decoding failure rate at low error levels.

IEEE Access•Dec 26, 2025•1 citation

Rate-Adaptive LDPC-based key reconciliation for high performance quantum key distribution

Jesús Martínez-Mateo, José Luis Rosales, Vicente Martín Ayuso

The postprocessing or secret-key distillation process in quantum key distribution (QKD) mainly involves two well-known procedures: information reconciliation and privacy amplification. Information or key reconciliation has been customarily studied in terms of efficiency. During this, some information needs to be disclosed for reconciling discrepancies in the exchanged keys. The leakage of information is lower bounded by a theoretical limit, and is usually parameterized by the reconciliation efficiency (or inefficiency), i.e. the ratio of additional information disclosed over the Shannon limit. Most techniques for reconciling errors in QKD try to optimize this parameter. For instance, the well-known Cascade (probably the most widely used procedure for reconciling errors in QKD) was recently shown to have an average efficiency of 1.05 at the cost of a high interactivity (number of exchanged messages). Modern coding techniques, such as rate-adaptive low-density parity-check (LDPC) codes were also shown to achieve similar efficiency values exchanging only one message, or even better values with few interactivity and shorter block-length codes.

•Jan 1, 2015•0 citations

Covert Communications-Based Information Reconciliation for Quantum Key Distribution Protocols

John Gariano, Ivan B. Djordjević

The rate at which a secure key can be generated in a quantum key distribution (QKD) protocol is limited by the channel loss and the quantum bit-error rate (QBER). Increases to the QBER can stem from detector noise, channel noise, or the presence of an eavesdropper, Eve. Eve is capable of obtaining information of the unsecure key by performing an attack on the quantum channel or by listening to all discussion performed via a noiseless public channel. Conventionally a QKD protocol will perform the information reconciliation over the authenticated public channel, revealing the parity bits used to correct for any quantum bit errors. In this invited paper, the possibility of limiting the information revealed to Eve during the information reconciliation is considered. Using a covert communication channel for the transmission of the parity bits, secure key rates are possible at much higher QBERs. This is demonstrated through the simulation of a polarization based QKD system implementing the BB84 protocol, showing significant improvement of the SKRs over the conventional QKD protocols.

International Conference on Transparent Optical Networks•Jul 1, 2019•2 citations

Efficient Rate-Adaptive Reconciliation Based on LDPC Accumulate Codes for Quantum Key Distribution

Tharathorn Phromsa‐ard, Patcharapong Treeviriyanupab, Paramin Sangwongngam +4 more

In this paper, a rate-adaptive method is proposed an alternative reconciliation protocol by employing the LDPC-accumulate codes to the practical implementation in the quantum key distribution (QKD). The proposed rate-adaptive reconciliation is adapted in the Slepian-Wolf scheme where specific low-density parity-check (LDPC) codes are constructed by accumulated syndrome encoding/decoding. Its objective is to skip the step of quantum bit error rate (QBER) estimation by the traditional key sampling that increases the final secret key length in practice. From the numerical results, the proposed method achieves a good performance in terms of the number of disclosed bits and reconciliation efficiency comparable to the conventional Winnow, Cascade, and fixed-rate compatible LDPC based protocols. Moreover, it can cover the possible cases of error rates in the QKD system. Therefore, method is suitable for the highspeed discrete-variable QKD applications.

International Technical Conference on Circuits/Systems, Computers and Communications (ITC-CSCC)•Jun 1, 2015•0 citations

การประมาณคาชองสญญาณดวยภาวะนาจะเปนสงสดสำหรบการไกลเกลยความผดพลาดแบบปรบอตราเขารหสเหมาะสมกบการกระจายกญแจรหสลบเชงควอนตม

พัชรพงษ์ ตรีวิริยานุภาพ, ธราธร พรมสะอาด

การกระจายกุญแจรหัสลับเชิงควอนตัมถือเป็นหนึ่งในเทคโนโลยีความปลอดภัยด้านการสื่อสาร โดยอาศัยหลักกลศาสตร์ควอนตัมเพื่อกำเนิดและแลกเปลี่ยนข้อมูลกุญแจรหัสลับระหว่างคู่สื่อสารให้มีความปลอดภัยสูงสุดสำหรับระบบวิทยาการรหัสลับ ซึ่งต้องอาศัยกระบวนการไกล่เกลี่ยความผิดพลาดเพื่อจุดประสงค์ในการยืนยันความถูกต้องของข้อมูลกุญแจรหัสลับระหว่างคู่สื่อสารให้มีค่าที่ตรงกัน ในบทความนี้ นำเสนอวิธีการประมาณค่าอัตราความผิดพลาดของช่องสัญญาณเชิงควอนตัมบนพื้นฐานของการประมาณค่าภาวะน่าจะเป็นสูงสุดจากชุดข้อมูลซินโดรมในระหว่างขั้นตอนการไกล่เกลี่ยความผิดพลาดสำหรับการปรับค่าอัตราการเข้ารหัสให้เหมาะสมกับความผิดพลาดของบิตข้อมูลกุญแจเชิงควอนตัมที่เกิดขึ้นในแต่ละช่วงเวลาด้วยรหัสตรวจสอบพาริตี้แบบความหนาแน่นต่ำ ตลอดจนการนำมาประยุกต์ใช้แทนขั้นตอนการเปิดเผยบิตข้อมูลกุญแจบางส่วนที่สูญเสียไปในการประมาณค่าความผิดพลาดแบบดั้งเดิม นำไปสู่ผลลัพธ์ของขนาดบิตข้อมูลกุญแจที่เพิ่มสูงขึ้น โดยจากการวิเคราะห์และทดสอบผลพบว่า วิธีการที่นำเสนอให้ความแม่นยำในการประมาณค่าอัตราความผิดพลาดครอบคลุมเงื่อนไขของการกระจายกุญแจรหัสลับเชิงควอนตัม นำไปสู่การเพิ่มประสิทธิภาพการไกล่เกลี่ยความผิดพลาดที่สูงขึ้นทั้งในด้านความปลอดภัยและอัตราการกำเนิดกุญแจรหัสลับ สนับสนุนการประยุกต์ใช้งานจริงในระบบการกระจายกุญแจรหัสลับเชิงควอนตัมความเร็วสูงQuantum Key Distribution (QKD), one of the communication security technologies, employs the properties of quantum mechanics to guarantee and exchange the perfectly-secured key generation between two legitimate parties for cryptographic purposes. The reconciliation process is required to correct the transmission error after the distribution of quantum objects. In this paper, the channel parameter estimation is proposed to estimate the error rate in the quantum channel by using the Maximum-Likelihood Estimation (MLE) based on the syndrome information for rate-adaptive reconciliation. The specific Low-Density Parity-Check (LDPC) codes are adapted to optimize their coding rates responding to the possible cases of error in QKD. The proposed method can be applied to avoid wasting sample keys in the traditional channel estimation, and led to increase the final secret key length. The simulation results show an accuracy of the estimated quantum bit error rate (QBER) for covering the range in QKD system. The gain of rate-adaptive reconciliation based on MLE confirms an improvement in the reconciliation efficiency that significantly impacts on the achievable secret key generation rate for high QKD throughput applications.

The Journal of King Mongkut s University of Technology North Bangkok•Nov 1, 2016•0 citations
Quantum Key Distribution (QKD) is a promising field in modern cryptography where the security of key information is guaranteed by the laws of quantum mechanics. One of the key stages in QKD protocols is error estimation and reconciliation in the secret key. This procedure requires the transmission of a certain number of secret key bits over a public channel. Such transmission leads to disclosing these bits to a potential eavesdropper. The fraction of disclosed bits—the sampling rate-largely depends on the chosen approach for preliminary error estimation in the channel. This work is devoted to the optimization of the sampling rate for an LDPC code from the 5G\mathbf{5 G}5G standard. The results of our experiments show that for a QBER below 0.2 and key lengths of 264, 528, 792, and 1056 bits, it is necessary to disclose no more than 18%,11%,10%18 \%, 11 \%, 10 \%18%,11%,10%, and 7%7 \%7% of the key bits for error estimation, respectively. Furthermore, the proposed algorithm allows for similar optimization for any information reconciliation protocols and actual quantum bit error rates.
The purpose of reconciliation, one of classical aspects of quantum key distribution (QKD) protocol, is to mitigate errors after the distribution of quantum information over a quantum channel. In this paper, a rate-adaptive method is proposed by means of a channel coding scheme where specific low-density parity-check (LDPC) codes are adapted in the Slepian-Wolf coding system. Puncturing and shortening techniques are adopted to optimize their coding rates with all possible cases of error in QKD. This successful method utilizes the knowledge of the quantum bit error rate (QBER) based on the maximum-likelihood estimator with respect to the syndrome information. Its benefit is that avoids wasting sample keys in the traditional channel estimation and thus increases the size of the final secret key. Evidently, simulation results confirm an improvement in the reconciliation efficiency with minimal interaction that suitable for high QKD throughput applications.
Error correction is a crucial stage in quantum key distribution (QKD) protocols—a promising field of modern cryptography where the secrecy of the shared key information is guaranteed by the laws of quantum mechanics. Currently, there are many effective approaches to error correction in QKD. However, most of them, due to their generic nature, fail to leverage the specific features of particular protocol implementations. This work demonstrates that accounting for the hardware specifics of a QKD system implementing the time-bin protocol enables a significant increase in error correction performance. For the considered QKD system, we have experimentally obtained estimates of the Quantum Bit Error Rate (QBER) observed for each combination of bit and detector. The differences in the obtained estimates reveal that the quantum channel can be modeled as a non-uniform binary channel. Furthermore, based on computational experiments with a model of the quantum channel, it was established that adapting the error correction procedure to its properties can achieve up to a 2.7-fold reduction in the LDPC code decoding failure rate at low error levels.
The postprocessing or secret-key distillation process in quantum key distribution (QKD) mainly involves two well-known procedures: information reconciliation and privacy amplification. Information or key reconciliation has been customarily studied in terms of efficiency. During this, some information needs to be disclosed for reconciling discrepancies in the exchanged keys. The leakage of information is lower bounded by a theoretical limit, and is usually parameterized by the reconciliation efficiency (or inefficiency), i.e. the ratio of additional information disclosed over the Shannon limit. Most techniques for reconciling errors in QKD try to optimize this parameter. For instance, the well-known Cascade (probably the most widely used procedure for reconciling errors in QKD) was recently shown to have an average efficiency of 1.05 at the cost of a high interactivity (number of exchanged messages). Modern coding techniques, such as rate-adaptive low-density parity-check (LDPC) codes were also shown to achieve similar efficiency values exchanging only one message, or even better values with few interactivity and shorter block-length codes.
The rate at which a secure key can be generated in a quantum key distribution (QKD) protocol is limited by the channel loss and the quantum bit-error rate (QBER). Increases to the QBER can stem from detector noise, channel noise, or the presence of an eavesdropper, Eve. Eve is capable of obtaining information of the unsecure key by performing an attack on the quantum channel or by listening to all discussion performed via a noiseless public channel. Conventionally a QKD protocol will perform the information reconciliation over the authenticated public channel, revealing the parity bits used to correct for any quantum bit errors. In this invited paper, the possibility of limiting the information revealed to Eve during the information reconciliation is considered. Using a covert communication channel for the transmission of the parity bits, secure key rates are possible at much higher QBERs. This is demonstrated through the simulation of a polarization based QKD system implementing the BB84 protocol, showing significant improvement of the SKRs over the conventional QKD protocols.
In this paper, a rate-adaptive method is proposed an alternative reconciliation protocol by employing the LDPC-accumulate codes to the practical implementation in the quantum key distribution (QKD). The proposed rate-adaptive reconciliation is adapted in the Slepian-Wolf scheme where specific low-density parity-check (LDPC) codes are constructed by accumulated syndrome encoding/decoding. Its objective is to skip the step of quantum bit error rate (QBER) estimation by the traditional key sampling that increases the final secret key length in practice. From the numerical results, the proposed method achieves a good performance in terms of the number of disclosed bits and reconciliation efficiency comparable to the conventional Winnow, Cascade, and fixed-rate compatible LDPC based protocols. Moreover, it can cover the possible cases of error rates in the QKD system. Therefore, method is suitable for the highspeed discrete-variable QKD applications.
การกระจายกุญแจรหัสลับเชิงควอนตัมถือเป็นหนึ่งในเทคโนโลยีความปลอดภัยด้านการสื่อสาร โดยอาศัยหลักกลศาสตร์ควอนตัมเพื่อกำเนิดและแลกเปลี่ยนข้อมูลกุญแจรหัสลับระหว่างคู่สื่อสารให้มีความปลอดภัยสูงสุดสำหรับระบบวิทยาการรหัสลับ ซึ่งต้องอาศัยกระบวนการไกล่เกลี่ยความผิดพลาดเพื่อจุดประสงค์ในการยืนยันความถูกต้องของข้อมูลกุญแจรหัสลับระหว่างคู่สื่อสารให้มีค่าที่ตรงกัน ในบทความนี้ นำเสนอวิธีการประมาณค่าอัตราความผิดพลาดของช่องสัญญาณเชิงควอนตัมบนพื้นฐานของการประมาณค่าภาวะน่าจะเป็นสูงสุดจากชุดข้อมูลซินโดรมในระหว่างขั้นตอนการไกล่เกลี่ยความผิดพลาดสำหรับการปรับค่าอัตราการเข้ารหัสให้เหมาะสมกับความผิดพลาดของบิตข้อมูลกุญแจเชิงควอนตัมที่เกิดขึ้นในแต่ละช่วงเวลาด้วยรหัสตรวจสอบพาริตี้แบบความหนาแน่นต่ำ ตลอดจนการนำมาประยุกต์ใช้แทนขั้นตอนการเปิดเผยบิตข้อมูลกุญแจบางส่วนที่สูญเสียไปในการประมาณค่าความผิดพลาดแบบดั้งเดิม นำไปสู่ผลลัพธ์ของขนาดบิตข้อมูลกุญแจที่เพิ่มสูงขึ้น โดยจากการวิเคราะห์และทดสอบผลพบว่า วิธีการที่นำเสนอให้ความแม่นยำในการประมาณค่าอัตราความผิดพลาดครอบคลุมเงื่อนไขของการกระจายกุญแจรหัสลับเชิงควอนตัม นำไปสู่การเพิ่มประสิทธิภาพการไกล่เกลี่ยความผิดพลาดที่สูงขึ้นทั้งในด้านความปลอดภัยและอัตราการกำเนิดกุญแจรหัสลับ สนับสนุนการประยุกต์ใช้งานจริงในระบบการกระจายกุญแจรหัสลับเชิงควอนตัมความเร็วสูงQuantum Key Distribution (QKD), one of the communication security technologies, employs the properties of quantum mechanics to guarantee and exchange the perfectly-secured key generation between two legitimate parties for cryptographic purposes. The reconciliation process is required to correct the transmission error after the distribution of quantum objects. In this paper, the channel parameter estimation is proposed to estimate the error rate in the quantum channel by using the Maximum-Likelihood Estimation (MLE) based on the syndrome information for rate-adaptive reconciliation. The specific Low-Density Parity-Check (LDPC) codes are adapted to optimize their coding rates responding to the possible cases of error in QKD. The proposed method can be applied to avoid wasting sample keys in the traditional channel estimation, and led to increase the final secret key length. The simulation results show an accuracy of the estimated quantum bit error rate (QBER) for covering the range in QKD system. The gain of rate-adaptive reconciliation based on MLE confirms an improvement in the reconciliation efficiency that significantly impacts on the achievable secret key generation rate for high QKD throughput applications.