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arXiv · 1910.11407

Tight finite-key security for twin-field quantum key distribution

Guillermo Currás-Lorenzo·Alvaro Navarrete·Koji Azuma·Go Kato·Marcos Curty·Mohsen Razavi
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Abstract

Quantum key distribution (QKD) offers a reliable solution to communication problems that require long-term data security. For its widespread use, however, the rate and reach of QKD systems must be improved. Twin-field (TF) QKD is a step forward toward this direction, with early demonstrations suggesting it can beat the current rate-versus-distance records. A recently introduced variant of TF-QKD is particularly suited for experimental implementation, and has been shown to offer a higher key rate than other variants in the asymptotic regime where users exchange an infinite number of signals. Here, we extend the security of this protocol to the finite-key regime, showing that it can overcome the fundamental bounds on point-to-point QKD with around $10^{10}$ transmitted signals. Within distance regimes of interest, our analysis offers higher key rates than those of alternative variants. Moreover, some of the techniques we develop are applicable to the finite-key analysis of other QKD protocols.

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Guillermo Currás-Lorenzo, Alvaro Navarrete, Koji Azuma, Go Kato, Marcos Curty, Mohsen Razavi. 2019-10-24. Tight finite-key security for twin-field quantum key distribution. https://doi.org/10.1038/s41534-020-00345-3

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