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

Scientific Reports

Practical, high-speed Gaussian coherent state continuous variable quantum key distribution with real-time parameter monitoring, optimised slicing, and post-processed key distillation

Amanda Weerasinghe, Muataz Alhussein, Adam Alderton, A. Wonfor, Richard V. Penty

Published Dec 6, 2023• 9 citations
Publisher

Abstract

Gaussian coherent state continuous variable quantum key distribution has gained interest owing to its security and compatibility with classical coherent optical fibre networks. For successful system deployment it is necessary to implement practical high speed systems which distil keys efficiently. Here, we demonstrate a Gaussian coherent state continuous variable quantum key distribution system at a 50 MHz symbol rate. Unlike most demonstrations to date which measure excess noise and infer key rates from this, we record signals in real time and distil keys. We also demonstrate, for the first time, slice reconciliation with optimised guard bands to maximise achievable secret key rates. Using this optimisation with multilevel slicing, a record 5 Mb/s secret key rate after a transmission distance of 25 km is achieved. This is a significant improvement on the 3 Mb/s secret key rate which is achieved with single level optimised slice reconciliation.

DOI
10.1038/s41598-023-47517-7

Related papers

Practical, high-speed Gaussian coherent state continuous variable quantum key distribution with real-time parameter monitoring, optimised slicing, and post-processed key distillation

Amanda Weerasinghe, Muataz Alhussein, Adam Alderton +2 more

Abstract Gaussian coherent state continuous variable quantum key distribution has gained interest owing to its security and compatibility with classical coherent optical fibre networks. For successful system deployment it is necessary to implement practical high speed systems which distil keys efficiently. Here, we demonstrate a Gaussian coherent state continuous variable quantum key distribution system at a 50 MHz symbol rate. Unlike most demonstrations to date which measure excess noise and infer key rates from this, we record signals in real time and distil keys. We also demonstrate, for the first time, slice reconciliation with optimised guard bands to maximise achievable secret key rates. Using this optimisation with multilevel slicing, a record 5 Mb/s secret key rate after a transmission distance of 25 km is achieved. This is a significant improvement on the 3 Mb/s secret key rate which is achieved with single level optimised slice reconciliation.

•Sep 12, 2023•1 citation

Experimental demonstration of practical high-speed Gaussian coherent state continuous-variable quantum key distribution with real-time parameter monitoring and key distillation

Amanda Weerasinghe, Muataz Alhussein, He Li +2 more

Gaussian modulated coherent state continuous variable quantum key distribution protocol is proven to provide high security while being compatible with classical coherent communication equipment. Here, we demonstrate a high-speed Gaussian modulated coherent state continuous variable quantum key distribution with a symbol rate of 40 MHz. Our system is consisted of field deployable data acquisition and processing hardware. We have also developed a software tool chain for recording data and parameter monitoring in real time. The data is then post processed to distill secret keys. We have achieved a secret key rate of 2.3 Mbps after all the post processing stages, at a transmission distance of 25 km.

Quantum Technology: Driving Commercialisation of an Enabling Science•Jan 11, 2023•2 citations

Practical high-speed Gaussian coherent state continuous variable quantum key distribution with real-time parameter monitoring and post-processed key distillation

Amanda Weerasinghe, Muataz Alhussein, He Li +2 more

We demonstrate Gaussian modulated continuous variable quantum key distribution at 50MHz symbol rate. Unlike most demonstrations, we record received signals in real-time and distil keys, producing a record 3Mb/s key rate after 25km transmission.

Optical Fiber Communication Conference•Jan 1, 2023•0 citations

Slice optimisation for high-speed Gaussian coherent state continuous variable quantum key distribution

Amanda Weerasinghe, Muataz Alhussein, He Li +2 more

We demonstrate, for the first time, slice reconciliation with optimised guard bands on Gaussian modulated continuous variable quantum key distribution. We produce a record 5Mb/s key rate after 25 km transmission distance with multilevel slicing.

•Jan 1, 2023•0 citations

Practical high-speed Gaussian coherent state continuous variable quantum key distribution with real-time parameter monitoring and post-processed key distillation

Amanda Weerasinghe, Muataz Alhussein, He Li +2 more

We demonstrate Gaussian modulated continuous variable quantum key distribution at 50MHz symbol rate. Unlike most demonstrations, we record received signals in real-time and distil keys, producing a record 3Mb/s key rate after 25km transmission.

Optical Fiber Communication Conference•Mar 1, 2023•0 citations

Demonstration of high-speed and low-complexity continuous variable quantum key distribution system with local local oscillator

Shengjun Ren, Shuai Yang, A. Wonfor +2 more

We present an experimental demonstration of the feasibility of the first 20 + Mb/s Gaussian modulated coherent state continuous variable quantum key distribution system with a locally generated local oscillator at the receiver (LLO-CVQKD). To increase the signal repetition rate, and hence the potential secure key rate, we equip our system with high-performance, wideband devices and design the components to support high repetition rate operation. We have successfully trialed the signal repetition rate as high as 500 MHz. To reduce the system complexity and correct for any phase shift during transmission, reference pulses are interleaved with quantum signals at Alice. Customized monitoring software has been developed, allowing all parameters to be controlled in real-time without any physical setup modification. We introduce a system-level noise model analysis at high bandwidth and propose a new 'combined-optimization' technique to optimize system parameters simultaneously to high precision. We use the measured excess noise, to predict that the system is capable of realizing a record 26.9 Mb/s key generation in the asymptotic regime over a 15 km signal mode fibre. We further demonstrate the potential for an even faster implementation.

Scientific Reports•May 4, 2021•61 citations
Gaussian coherent state continuous variable quantum key distribution has gained interest owing to its security and compatibility with classical coherent optical fibre networks. For successful system deployment it is necessary to implement practical high speed systems which distil keys efficiently. Here, we demonstrate a Gaussian coherent state continuous variable quantum key distribution system at a 50 MHz symbol rate. Unlike most demonstrations to date which measure excess noise and infer key rates from this, we record signals in real time and distil keys. We also demonstrate, for the first time, slice reconciliation with optimised guard bands to maximise achievable secret key rates. Using this optimisation with multilevel slicing, a record 5 Mb/s secret key rate after a transmission distance of 25 km is achieved. This is a significant improvement on the 3 Mb/s secret key rate which is achieved with single level optimised slice reconciliation.
Abstract Gaussian coherent state continuous variable quantum key distribution has gained interest owing to its security and compatibility with classical coherent optical fibre networks. For successful system deployment it is necessary to implement practical high speed systems which distil keys efficiently. Here, we demonstrate a Gaussian coherent state continuous variable quantum key distribution system at a 50 MHz symbol rate. Unlike most demonstrations to date which measure excess noise and infer key rates from this, we record signals in real time and distil keys. We also demonstrate, for the first time, slice reconciliation with optimised guard bands to maximise achievable secret key rates. Using this optimisation with multilevel slicing, a record 5 Mb/s secret key rate after a transmission distance of 25 km is achieved. This is a significant improvement on the 3 Mb/s secret key rate which is achieved with single level optimised slice reconciliation.
Gaussian modulated coherent state continuous variable quantum key distribution protocol is proven to provide high security while being compatible with classical coherent communication equipment. Here, we demonstrate a high-speed Gaussian modulated coherent state continuous variable quantum key distribution with a symbol rate of 40 MHz. Our system is consisted of field deployable data acquisition and processing hardware. We have also developed a software tool chain for recording data and parameter monitoring in real time. The data is then post processed to distill secret keys. We have achieved a secret key rate of 2.3 Mbps after all the post processing stages, at a transmission distance of 25 km.
We present an experimental demonstration of the feasibility of the first 20 + Mb/s Gaussian modulated coherent state continuous variable quantum key distribution system with a locally generated local oscillator at the receiver (LLO-CVQKD). To increase the signal repetition rate, and hence the potential secure key rate, we equip our system with high-performance, wideband devices and design the components to support high repetition rate operation. We have successfully trialed the signal repetition rate as high as 500 MHz. To reduce the system complexity and correct for any phase shift during transmission, reference pulses are interleaved with quantum signals at Alice. Customized monitoring software has been developed, allowing all parameters to be controlled in real-time without any physical setup modification. We introduce a system-level noise model analysis at high bandwidth and propose a new 'combined-optimization' technique to optimize system parameters simultaneously to high precision. We use the measured excess noise, to predict that the system is capable of realizing a record 26.9 Mb/s key generation in the asymptotic regime over a 15 km signal mode fibre. We further demonstrate the potential for an even faster implementation.