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

2017/04/30 by Cosmo Lupo, Carlo Ottaviani, Panagiotis Papanastasiou +1 · 1 citation
Physics and Astronomy · #quant-ph

paper · pdf · doi:10.1103/physreva.97.052327

published as Phys. Rev. A 97, 052327 (2018) · v4: close to the published version (which is shorter than previous arXiv versions)

arxiv created 2018/06/09 · arxiv updated 2018/06/12

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 10⁷-10⁹ quantum signal transmissions, depending on loss and noise, and on the required level of security.

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• Continuous-variables quantum cryptography: asymptotic and finite-size security analysis

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