Boosting quantum key distribution via the end-to-end loss control

TL;DR

This paper introduces an adaptive end-to-end line tomography method that significantly enhances quantum key distribution rates by real-time detection and response, potentially surpassing repeaterless rate-distance limits.

Contribution

It presents a novel real-time channel intervention detection technique that adaptively optimizes QKD parameters, improving key rates without quantum repeaters.

Findings

Substantial increase in QKD key rates achieved.

Real-time intervention detection enables adaptive optimization.

Potential to surpass repeaterless rate-distance limit.

Abstract

With the rise of quantum technologies, data security increasingly relies on quantum cryptography and its most notable application, quantum key distribution (QKD). Yet, current technological limitations, in particular, the unavailability of quantum repeaters, cause relatively low key distribution rates in practical QKD implementations. Here, we demonstrate a remarkable improvement in the QKD performance using end-to-end line tomography for the wide class of relevant protocols. Our approach is based on the real-time detection of interventions in the transmission channel, enabling an adaptive response that modifies the QKD setup and post-processing parameters, leading, thereby, to a substantial increase in the key distribution rates. Our findings provide everlastingly secure efficient quantum cryptography deployment potentially overcoming the repeaterless rate-distance limit.