English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Zendy Plus

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Zendy Tools

Zendy Open

High efficiency postprocessing of continuous-variable quantum keydistribution system has a significant impact on the secret key rate andtransmission distance of the system. Currently, the postprocessing mainlycontains four steps in the following order: sifting, parameter estimation,information reconciliation, and privacy amplification. For a quantum channelwith unknown prior characteristics, part of the raw keys (typically half) haveto be sacrificed to estimate the channel parameters, which is used to assist inerror correction (part of information reconciliation) and estimate the secretkey rate. This introduces a tradeoff between the secret key rate and theaccuracy of parameter estimation when considering the finite-size effect. Inthis paper, we propose a high efficiency postprocessing method which uses allthe raw keys for both parameter estimation and key extraction. It is realizedby exchanging the order of parameter estimation and information reconciliation,while the other steps remain unchanged. After the sifting step, the extra data(used for phase compensation and synchronization etc) can be used to roughlyestimate the quantum channel parameters, or using the estimated results of lastblock, thus the error correction can be realized normally. After the success oferror correction, the reconciler recovers the raw keys of the other side by areverse mapping function. Then she uses all the raw keys of both sides forparameter estimation to estimate the quantum channel parameters and calculatethe secret key rate of the system. Finally, they perform the privacyamplification step to obtain the unconditional security keys. We show that thismethod improves the accuracy of parameter estimation and the secret key rate ofcontinuous-variable quantum key distribution system.

High Efficiency Postprocessing for Continuous-variable Quantum Key Distribution: Using All Raw Keys for Parameter Estimation and Key Extraction