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arXiv · 1704.07924

Continuous-variable measurement-device-independent quantum key distribution: Composable security against coherent attacks

Cosmo Lupo·Carlo Ottaviani·Panagiotis Papanastasiou·Stefano Pirandola
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Abstract

We present a rigorous security analysis of Continuous-Variable Measurement-Device Independent Quantum Key Distribution (CV MDI QKD) in a finite size scenario. The security proof is obtained in two steps: by first assessing the security against collective Gaussian attacks, and then extending to the most general class of coherent attacks via the Gaussian de Finetti reduction. Our result combines recent state-of-the-art security proofs for CV QKD with new findings about min-entropy calculus and parameter estimation. In doing so, we improve the finite-size estimate of the secret key rate. Our conclusions confirm that CV MDI protocols allow for high rates on the metropolitan scale, and may achieve a nonzero secret key rate against the most general class of coherent attacks after 10^7-10^9 quantum signal transmissions, depending on loss and noise, and on the required level of security.

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Cosmo Lupo, Carlo Ottaviani, Panagiotis Papanastasiou, Stefano Pirandola. 2018-06-09. Continuous-variable measurement-device-independent quantum key distribution: Composable security against coherent attacks. https://doi.org/10.1103/physreva.97.052327

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