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Practical unclonable encryption with continuous variables

Arpan Akash Ray and Boris Škorić

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Phys. Rev. A 114, 032410 – Published 4 September, 2026

DOI: https://doi.org/10.1103/kkzp-w2hc

Abstract

We propose the first continuous-variable (CV) unclonable encryption scheme, extending the paradigm of quantum encryption of classical messages to CV systems. In our construction, a classical message is first encrypted classically and then encoded using an error-correcting code. Each bit of the codeword is mapped to a CV mode by creating a coherent state which is squeezed in the q or p quadrature direction, with a small displacement that encodes the bit. The squeezing directions are part of the encryption key. We prove unclonability in the framework introduced by Broadbent and Lord, via a reduction of the cloning game to a CV monogamy-of-entanglement game. Furthermore, we demonstrate that our scheme can be readily implemented with current technology. By incorporating realistic imperfections such as channel noise and detector inefficiencies, we show that the protocol remains robust under these conditions.

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Outline

Information

Phys. Rev. A 114, 032410– Published 4 September, 2026
  • Received 7 November 2025
  • Revised 26 May 2026
  • Accepted 15 July 2026
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Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI.

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