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

IEEE Photonics Conference

Discretized Gaussian Modulation-Based Continuous Variable (CV)-QKD

Ivan B. Djordjević

Published Sep 1, 2019• 2 citations
Publisher

Abstract

To overcome the low-reconciliation-efficiency problem of Gaussian modulation (GM)-based-CV-QKD, we propose to use discretized-GM-based-CV-QKD. This scheme has complexity and reconciliation-efficiency similar to discrete modulation (DM)-based-CV-QKD and at the same time solves for the problem of nonexistence of strict security proofs for DM-CV-QKD under collective attacks.

DOI
10.1109/ipcon.2019.8908312

Related papers

On the Discretized Gaussian Modulation (DGM)- Based Continuous Variable-QKD

Ivan B. Djordjević

To overcome the low reconciliation efficiency problem of Gaussian modulation (GM)-based-continuous variable (CV)-quantum key distribution (QKD), in this paper, we propose to use discretized GM (DGM)-based-CV-QKD. The proposed CV-QKD scheme has complexity and reconciliation efficiency similar to that of discrete modulation (DM)-based-CV-QKD and at the same time solves for the problem of the nonexistence of strict security proofs for the DM-CV-QKD under the collective attacks. We demonstrate that the 32-points-based DGM CV-QKD can closely approach the theoretical SKR-limit in medium and high channel losses regimes. On the other hand, the 64-points-based DGM CV-QKD scheme closely approaches the SKR-limit for all channel losses.

IEEE Access•Jan 1, 2019•20 citations

Optimized-Eight-State CV-QKD Protocol Outperforming Gaussian Modulation Based Protocols

Ivan B. Djordjević

In this paper, an optimized-eight-state CV-QKD protocol is proposed significantly outperforming previously introduced discrete modulation (DM) protocols as well as the corresponding Gaussian modulation (GM)-based CV-QKD protocols for practical reconciliation efficiencies values in terms of both secret-key rate (SKR) and achievable distance. The proposed CV-QKD protocol also outperforms, in terms of SKR, the corresponding high-cost single-photon DV-QKD scheme, employing an array of multiplexed single-photon detectors, for several orders of magnitude. We also describe a generalized RF-assisted CV-QKD scheme with heterodyne detection applicable to arbitrary DM scheme, insensitive to the laser phase noise and frequency offset fluctuations.

IEEE photonics journal•Jun 6, 2019•32 citations

Hybrid QKD Protocol Outperforming Both DV- and CV-QKD Protocols

Ivan B. Djordjević

To overcome the limitations of both discrete variable (DV) and continuous variable (CV) QKD protocols, in this paper, a hybrid QKD protocol is proposed. In the proposed hybrid QKD protocol, Alice simultaneously performs discrete modulation (DM)-based encoding for CV-QKD subsystem and time-phase encoding for DV-QKD on a transmitter side and transmits such hybrid encoded pulse with optimized average number of photons per pulse. On receiver side, Bob employs a 1:2 optical space switch to select either DV-QKD receiver or CV-QKD receiver with the optimized probability of selection. Other compatible CV-QKD and DV-QKD protocols can also be used in hybrid QKD. Bob further performs the classical postprocessing applied to both subsystems so that resulting joint secure key is derived from both subsystems. The proposed hybrid QKD protocol significantly outperforms previously introduced both Gaussian modulation (GM)- and DM-based CV-QKD protocols as well as DV-QKD protocols in terms of both secret-key rate and achievable transmission distance.

IEEE photonics journal•Oct 11, 2019•29 citations

Hybrid DV-CV QKD Outperforming Existing QKD Protocols in Terms of Secret-Key Rate and Achievable Distance

Ivan B. Djordjević

To overcome the limitations of both discrete variable (DV) and continuous variable (CV) QKD protocols, in this paper, a hybrid DV-CV QKD protocol is proposed. In the proposed hybrid QKD protocol, Alice simultaneously performs discrete modulation (DM)-based encoding for CV-QKD subsystem and time-phase encoding for DV-QKD on a transmitter side. On receiver side, Bob employs a 1:2 optical space switch to select either DV-QKD receiver or CV-QKD receiver with the optimized probability of selection. Bob further performs the classical postprocessing applied to both subsystems so that resulting joint secure key is derived from both subsystems. The proposed hybrid QKD protocol significantly outperforms previously introduced both Gaussian modulation (GM)- and DM-based CV-QKD protocols as well as DV-QKD protocols in terms of both secret-key rate (SKR) and achievable transmission distance.

International Conference on Transparent Optical Networks•Jul 1, 2019•6 citations

Long-distance continuous-variable measurement-device-independent quantum key distribution with discrete modulation

Hongxin Ma, Peng Huang, Dongyun Bai +4 more

We propose a long-distance continuous-variable measurement-device-independent quantum key distribution (CV-MDI-QKD) protocol with discrete modulation. This kind of discrete-modulated scheme has good compatibility with efficient error correction code, which leads to higher reconciliation efficiency even at low signal-to-noise ratio. Security analysis shows that the proposed protocol is secure against arbitrary collective attacks in the asymptotic limit with the proper use of decoy states. With the use of discrete modulation, the proposed CV-MDI-QKD protocol has simpler implementation and outperforms previous protocols in terms of achievable maximal transmission distance, which precisely solved the bottleneck of the original Gaussian-modulated CV-MDI-QKD protocol.

arXiv:1812.05254•Physical Review A•Feb 20, 2019•65 citations

The security of practical post-selection in Gaussian-modulated continuous-variable quantum key distribution

Adam Alderton, Weerasinghe Weerasinghe, Muataz Alhussein +2 more

Abstract Gaussian-modulated coherent-state (GMCS) continuous-variable quantum key distribution (CV-QKD) offers a practical path to quantum-secured communication owing to its compatibility with existing optical fibre networks and use of mature security proofs. Achieving high secret key rates in real-time systems, however, requires post-processing schemes that are both information-theoretically efficient and computationally scalable. In previous experimental work 1 , we have demonstrated record real-time key rates using a one-round sliced reconciliation scheme with guard-band post-selection. Here, we present the corresponding theoretical framework and provide an asymptotic security analysis that considers arbitrary collective attacks, a much broader class of attacks than the usually assumed Gaussian collective attacks. The security analysis applies the entropic continuity of quantum channels justified by a quantum channel estimation procedure. In conditions of high noise, our scheme uses 500 times less classical communication than multidimensional reconciliation.

npj Quantum Information•Sep 26, 2026•0 citations
To overcome the low-reconciliation-efficiency problem of Gaussian modulation (GM)-based-CV-QKD, we propose to use discretized-GM-based-CV-QKD. This scheme has complexity and reconciliation-efficiency similar to discrete modulation (DM)-based-CV-QKD and at the same time solves for the problem of nonexistence of strict security proofs for DM-CV-QKD under collective attacks.
To overcome the low reconciliation efficiency problem of Gaussian modulation (GM)-based-continuous variable (CV)-quantum key distribution (QKD), in this paper, we propose to use discretized GM (DGM)-based-CV-QKD. The proposed CV-QKD scheme has complexity and reconciliation efficiency similar to that of discrete modulation (DM)-based-CV-QKD and at the same time solves for the problem of the nonexistence of strict security proofs for the DM-CV-QKD under the collective attacks. We demonstrate that the 32-points-based DGM CV-QKD can closely approach the theoretical SKR-limit in medium and high channel losses regimes. On the other hand, the 64-points-based DGM CV-QKD scheme closely approaches the SKR-limit for all channel losses.
In this paper, an optimized-eight-state CV-QKD protocol is proposed significantly outperforming previously introduced discrete modulation (DM) protocols as well as the corresponding Gaussian modulation (GM)-based CV-QKD protocols for practical reconciliation efficiencies values in terms of both secret-key rate (SKR) and achievable distance. The proposed CV-QKD protocol also outperforms, in terms of SKR, the corresponding high-cost single-photon DV-QKD scheme, employing an array of multiplexed single-photon detectors, for several orders of magnitude. We also describe a generalized RF-assisted CV-QKD scheme with heterodyne detection applicable to arbitrary DM scheme, insensitive to the laser phase noise and frequency offset fluctuations.
To overcome the limitations of both discrete variable (DV) and continuous variable (CV) QKD protocols, in this paper, a hybrid QKD protocol is proposed. In the proposed hybrid QKD protocol, Alice simultaneously performs discrete modulation (DM)-based encoding for CV-QKD subsystem and time-phase encoding for DV-QKD on a transmitter side and transmits such hybrid encoded pulse with optimized average number of photons per pulse. On receiver side, Bob employs a 1:2 optical space switch to select either DV-QKD receiver or CV-QKD receiver with the optimized probability of selection. Other compatible CV-QKD and DV-QKD protocols can also be used in hybrid QKD. Bob further performs the classical postprocessing applied to both subsystems so that resulting joint secure key is derived from both subsystems. The proposed hybrid QKD protocol significantly outperforms previously introduced both Gaussian modulation (GM)- and DM-based CV-QKD protocols as well as DV-QKD protocols in terms of both secret-key rate and achievable transmission distance.
To overcome the limitations of both discrete variable (DV) and continuous variable (CV) QKD protocols, in this paper, a hybrid DV-CV QKD protocol is proposed. In the proposed hybrid QKD protocol, Alice simultaneously performs discrete modulation (DM)-based encoding for CV-QKD subsystem and time-phase encoding for DV-QKD on a transmitter side. On receiver side, Bob employs a 1:2 optical space switch to select either DV-QKD receiver or CV-QKD receiver with the optimized probability of selection. Bob further performs the classical postprocessing applied to both subsystems so that resulting joint secure key is derived from both subsystems. The proposed hybrid QKD protocol significantly outperforms previously introduced both Gaussian modulation (GM)- and DM-based CV-QKD protocols as well as DV-QKD protocols in terms of both secret-key rate (SKR) and achievable transmission distance.
We propose a long-distance continuous-variable measurement-device-independent quantum key distribution (CV-MDI-QKD) protocol with discrete modulation. This kind of discrete-modulated scheme has good compatibility with efficient error correction code, which leads to higher reconciliation efficiency even at low signal-to-noise ratio. Security analysis shows that the proposed protocol is secure against arbitrary collective attacks in the asymptotic limit with the proper use of decoy states. With the use of discrete modulation, the proposed CV-MDI-QKD protocol has simpler implementation and outperforms previous protocols in terms of achievable maximal transmission distance, which precisely solved the bottleneck of the original Gaussian-modulated CV-MDI-QKD protocol.
Abstract Gaussian-modulated coherent-state (GMCS) continuous-variable quantum key distribution (CV-QKD) offers a practical path to quantum-secured communication owing to its compatibility with existing optical fibre networks and use of mature security proofs. Achieving high secret key rates in real-time systems, however, requires post-processing schemes that are both information-theoretically efficient and computationally scalable. In previous experimental work 1 , we have demonstrated record real-time key rates using a one-round sliced reconciliation scheme with guard-band post-selection. Here, we present the corresponding theoretical framework and provide an asymptotic security analysis that considers arbitrary collective attacks, a much broader class of attacks than the usually assumed Gaussian collective attacks. The security analysis applies the entropic continuity of quantum channels justified by a quantum channel estimation procedure. In conditions of high noise, our scheme uses 500 times less classical communication than multidimensional reconciliation.