Unclonable Encryption with Continuous Variables

We propose the first continuous-variable (CV) unclonable encryption scheme, extending the paradigm of quantum encryption of classical messages (QECM) 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.

@article{ray2025_2503.02648,
  title={ Unclonable Encryption with Continuous Variables },
  author={ Arpan Akash Ray and Boris Škorić },
  journal={arXiv preprint arXiv:2503.02648},
  year={ 2025 }
}