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

Optics Letters

Experimental demonstration of decoy-three-state quantum key distribution with advantage distillation

Li Gong, Chen-Peng Hao, Zhi-Jiang Chen, Yang Wang, Xiang-Qun Fu, Jianhong Shi, Chun Hua Zhou, Hong-Wei Li

Published Oct 10, 2025• 0 citations
Publisher

Abstract

The advantage distillation (AD) method can significantly improve the bit error rate tolerance and transmission distance for different quantum key distribution (QKD) protocols. To enhance the transmission distance in a decoy-three-state QKD protocol, we analyze security using the AD method for the decoy-three-state QKD protocol with a weak-coherent source. The theoretical analysis results indicate that the AD method can significantly enhance the transmission distance of the decoy-three-state QKD protocol. Moreover, by applying the AD method, we experimentally realize the decoy-three-state QKD protocol with 130 km transmission distance. Our analysis results demonstrate that the AD method can significantly improve the performance of decoy-three-state QKD protocols, which can be applied in the quantum network in future research.

DOI
10.1364/ol.569050

Related papers

Improving the performance of practical decoy-state quantum key distribution with advantage distillation technology

Hong-Wei Li, Chun-Mei Zhang, Mu-Sheng Jiang +1 more

Abstract Quantum key distribution (QKD) provides a promising solution for sharing information-theoretic secret keys between two remote legitimate parties. To improve the maximal transmission distance and the maximal error rate tolerance, we apply the advantage distillation technology to analyze the security of practical decoy-state QKD systems. Based on the practical experimental parameters, the device-dependent QKD protocols and the measurement-device-independent QKD protocols have been respectively analyzed, and our analysis results demonstrate that the advantage distillation technology can significantly improve the performance of various QKD protocols. In the four-state and six-state device-dependent QKD protocols, we prove that the maximal transmission distance can be improved from 142 km to 180 km and from 146 km to 187 km respectively. In the four-state and six-state measurement-device-independent QKD protocols, we prove that the maximal transmission distance can be improved from 195 km to 273 km and from 200 km to 282 km respectively.

Communications Physics•Mar 11, 2022•51 citations

Experimental verification of on-chip quantum key distribution based on advantage distillation

Rui Zhang, Tian Yu, Bin Zhang +4 more

Quantum key distribution (QKD) has been extensively studied for practical applications. Advantage distillation (AD) represents a key technique to extract highly correlated bit pairs from weakly correlated ones, thus improving QKD protocol performance, particularly in large-error scenarios. However, its practical implementation remains under-explored. In this study, the AD is integrated into the three-intensity decoy-state BB84 protocol and its performance is demonstrated on a high-speed phase-encoding platform. The experimental system employs an asymmetric Mach-Zehnder interferometer (AMZI) fabricated on a silicon dioxide optical waveguide chip for phase encoding, which is benefited from its low coupling loss and minimum waveguide transmission loss. Phase-randomized weak coherent pulses, generated by a distributed feedback laser at 625 MHz, are modulated into decoy states of varying intensities. The signals are encoded via an AMZI and attenuated to single-photon levels before transmission. At the receiver, another AMZI demodulates the signals detected by avalanche photodiodes in gated mode. Experiments conducted at 50 km and 105 km demonstrate secure key rates of 104 kbits/s and 59 bits/s, respectively. The results at shorter distances closely match theoretical predictions, while slight deviations at 105 km are attributed to signal attenuation and noise. Despite these challenges, the results obtained at 105 km highlight the effectiveness of AD in enhancing secure key rates in the large-error scenario. This study confirms the potential of AD in extending secure communication range of QKD. By leveraging the high integration and scalability of silicon dioxide photonic chips, the proposed system lays a foundation for large-scale QKD deployment, paving the way for developing advanced protocols and real-world quantum networks.

Acta Physica Sinica•Dec 25, 2024•2 citations

Towards a Finite Size Analysis of Decoy-State Quantum Key Distribution with Advantage Distillation

Kleinpaß, Philipp, Treplin, Jonas, Orsucci, Davide

Quantum Key Distribution (QKD) allows two legitimate parties, Alice and Bob, to share a secret key with information-theoretic security, ensuring that an eavesdropper, Eve, cannot obtain any information about the key. A QKD protocol is provably secure only when the Quantum Bit Error Rate (QBER) is below a certain threshold and, therefore, the presence of noise inherently limits the maximum transmission distance. Advantage Distillation (AD) is a classical post-processing technique that enhances QKD protocols by increasing the maximum acceptable QBER and, thus, allows extending the communication range. AD operates by post-selecting blocks of bits and extracting fewer but highly correlated bits between Alice and Bob, which exhibit a reduced QBER, thus lowering the amount of information that has to be disclosed during the information reconciliation step. In this study, we present a new analytical expression for the secure key rate. This will enable a finite-size secure key length analysis of the decoy state version of the BB84 protocol including AD post-processing.

•Sep 1, 2024•0 citations

Reference-frame-independent quantum key distribution with advantage distillation

Jian-Rong Zhu, Chun-Mei Zhang, Rong Wang +1 more

Advantage distillation (AD) provides a means of separating highly correlated raw key bits from weakly correlated information in quantum key distribution (QKD). In this Letter, we apply the AD method to improve the performance of reference-frame-independent QKD (RFI-QKD). Simulation results show that, compared with RFI-QKD without AD, RFI-QKD with AD can tolerate higher system errors and obtain better performance on the secret key rate and transmission distance. Furthermore, we extend the AD method to RFI measurement-device-independent QKD (RFI-MDI-QKD) and demonstrate that the AD method can improve the performance of RFI-MDI-QKD more significantly.

Optics Letters•Dec 21, 2022•18 citations

Finite Size Analysis of Decoy-State BB84 with Advantage Distillation

Jonas Treplin, Philipp Kleinpaß, Davide Orsucci

Advantage Distillation (AD) is a classical post-processing technique that enhances Quantum Key Distribution (QKD) protocols by increasing the maximum acceptable Quantum Bit Error Rate (QBER) and thus extending the distance at which QKD links can be securely established. AD operates by post-selecting blocks of bits and extracting fewer high-fidelity bits, exhibiting a reduced QBER and thus lowering the amount of information that has to be disclosed during the information reconciliation step. In this work we present the first comprehensive finite key-size analysis of decoy-state BB84 enhanced via AD post-processing. We demonstrate that through the use of AD the maximum acceptable QBER increases from around $9.5\%$ to around $17.3\%$ for realistic key sizes. This result shows that substantial performance enhancements can be achieved in scenarios which are constrained by the maximum tolerable QBER via improvements of the post-processing method alone.

quant-pharXiv:2511.21665•Nov 27, 2025•0 citations

Improving the performance of practical wavelength division multiplexing decoy-state quantum key distribution with advantage distillation

Bumil Kim, Jun Heo

Quantum key distribution (QKD) is a promising method for sharing an information-theoretically secure secret key using the properties of quantum mechanics. Although QKD is the most practical field in quantum information science, its widespread adoption is constrained by high implementation costs. Despite the cost-effectiveness of propagating QKD with classical communication using wavelength division multiplexing (WDM), the noise generated by relatively strong classical signals degrades QKD performance. Even though several mitigation strategies exist, they often involve complexity or additional hardware. In this paper, we apply advantage distillation (AD) to enhance the performance of a practical decoy-state BB84 QKD system operating in a WDM environment. We perform finite-key analysis in both co-propagation and counter-propagation scenarios with three classical channels, and furthermore we examine the effects of varying the number of classical channels and the optical power per channel. A comparison of simulation results obtained with and without AD demonstrates that AD is robust to noise originating from classical channels. These results show that AD increases the secure key rate and transmission distance in the WDM-based QKD environment under both co-propagation and counter-propagation without requiring hardware changes. These findings suggest advantage distillation is a promising strategy for the widespread adoption of WDM-based QKD, including in challenging counter-propagation cases.

Scientific Reports•May 22, 2026•0 citations
The advantage distillation (AD) method can significantly improve the bit error rate tolerance and transmission distance for different quantum key distribution (QKD) protocols. To enhance the transmission distance in a decoy-three-state QKD protocol, we analyze security using the AD method for the decoy-three-state QKD protocol with a weak-coherent source. The theoretical analysis results indicate that the AD method can significantly enhance the transmission distance of the decoy-three-state QKD protocol. Moreover, by applying the AD method, we experimentally realize the decoy-three-state QKD protocol with 130 km transmission distance. Our analysis results demonstrate that the AD method can significantly improve the performance of decoy-three-state QKD protocols, which can be applied in the quantum network in future research.
Abstract Quantum key distribution (QKD) provides a promising solution for sharing information-theoretic secret keys between two remote legitimate parties. To improve the maximal transmission distance and the maximal error rate tolerance, we apply the advantage distillation technology to analyze the security of practical decoy-state QKD systems. Based on the practical experimental parameters, the device-dependent QKD protocols and the measurement-device-independent QKD protocols have been respectively analyzed, and our analysis results demonstrate that the advantage distillation technology can significantly improve the performance of various QKD protocols. In the four-state and six-state device-dependent QKD protocols, we prove that the maximal transmission distance can be improved from 142 km to 180 km and from 146 km to 187 km respectively. In the four-state and six-state measurement-device-independent QKD protocols, we prove that the maximal transmission distance can be improved from 195 km to 273 km and from 200 km to 282 km respectively.
Quantum key distribution (QKD) has been extensively studied for practical applications. Advantage distillation (AD) represents a key technique to extract highly correlated bit pairs from weakly correlated ones, thus improving QKD protocol performance, particularly in large-error scenarios. However, its practical implementation remains under-explored. In this study, the AD is integrated into the three-intensity decoy-state BB84 protocol and its performance is demonstrated on a high-speed phase-encoding platform. The experimental system employs an asymmetric Mach-Zehnder interferometer (AMZI) fabricated on a silicon dioxide optical waveguide chip for phase encoding, which is benefited from its low coupling loss and minimum waveguide transmission loss. Phase-randomized weak coherent pulses, generated by a distributed feedback laser at 625 MHz, are modulated into decoy states of varying intensities. The signals are encoded via an AMZI and attenuated to single-photon levels before transmission. At the receiver, another AMZI demodulates the signals detected by avalanche photodiodes in gated mode. Experiments conducted at 50 km and 105 km demonstrate secure key rates of 104 kbits/s and 59 bits/s, respectively. The results at shorter distances closely match theoretical predictions, while slight deviations at 105 km are attributed to signal attenuation and noise. Despite these challenges, the results obtained at 105 km highlight the effectiveness of AD in enhancing secure key rates in the large-error scenario. This study confirms the potential of AD in extending secure communication range of QKD. By leveraging the high integration and scalability of silicon dioxide photonic chips, the proposed system lays a foundation for large-scale QKD deployment, paving the way for developing advanced protocols and real-world quantum networks.
Quantum Key Distribution (QKD) allows two legitimate parties, Alice and Bob, to share a secret key with information-theoretic security, ensuring that an eavesdropper, Eve, cannot obtain any information about the key. A QKD protocol is provably secure only when the Quantum Bit Error Rate (QBER) is below a certain threshold and, therefore, the presence of noise inherently limits the maximum transmission distance. Advantage Distillation (AD) is a classical post-processing technique that enhances QKD protocols by increasing the maximum acceptable QBER and, thus, allows extending the communication range. AD operates by post-selecting blocks of bits and extracting fewer but highly correlated bits between Alice and Bob, which exhibit a reduced QBER, thus lowering the amount of information that has to be disclosed during the information reconciliation step. In this study, we present a new analytical expression for the secure key rate. This will enable a finite-size secure key length analysis of the decoy state version of the BB84 protocol including AD post-processing.
Advantage distillation (AD) provides a means of separating highly correlated raw key bits from weakly correlated information in quantum key distribution (QKD). In this Letter, we apply the AD method to improve the performance of reference-frame-independent QKD (RFI-QKD). Simulation results show that, compared with RFI-QKD without AD, RFI-QKD with AD can tolerate higher system errors and obtain better performance on the secret key rate and transmission distance. Furthermore, we extend the AD method to RFI measurement-device-independent QKD (RFI-MDI-QKD) and demonstrate that the AD method can improve the performance of RFI-MDI-QKD more significantly.
Advantage Distillation (AD) is a classical post-processing technique that enhances Quantum Key Distribution (QKD) protocols by increasing the maximum acceptable Quantum Bit Error Rate (QBER) and thus extending the distance at which QKD links can be securely established. AD operates by post-selecting blocks of bits and extracting fewer high-fidelity bits, exhibiting a reduced QBER and thus lowering the amount of information that has to be disclosed during the information reconciliation step. In this work we present the first comprehensive finite key-size analysis of decoy-state BB84 enhanced via AD post-processing. We demonstrate that through the use of AD the maximum acceptable QBER increases from around 9.5%9.5\%9.5% to around 17.3%17.3\%17.3% for realistic key sizes. This result shows that substantial performance enhancements can be achieved in scenarios which are constrained by the maximum tolerable QBER via improvements of the post-processing method alone.
Quantum key distribution (QKD) is a promising method for sharing an information-theoretically secure secret key using the properties of quantum mechanics. Although QKD is the most practical field in quantum information science, its widespread adoption is constrained by high implementation costs. Despite the cost-effectiveness of propagating QKD with classical communication using wavelength division multiplexing (WDM), the noise generated by relatively strong classical signals degrades QKD performance. Even though several mitigation strategies exist, they often involve complexity or additional hardware. In this paper, we apply advantage distillation (AD) to enhance the performance of a practical decoy-state BB84 QKD system operating in a WDM environment. We perform finite-key analysis in both co-propagation and counter-propagation scenarios with three classical channels, and furthermore we examine the effects of varying the number of classical channels and the optical power per channel. A comparison of simulation results obtained with and without AD demonstrates that AD is robust to noise originating from classical channels. These results show that AD increases the secure key rate and transmission distance in the WDM-based QKD environment under both co-propagation and counter-propagation without requiring hardware changes. These findings suggest advantage distillation is a promising strategy for the widespread adoption of WDM-based QKD, including in challenging counter-propagation cases.