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 errorcorrecting 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.

翻译：我们提出了首个基于连续变量（CV）的不可克隆加密方案，将经典消息的量子加密范式扩展至连续变量系统。在该方案中，经典消息首先经过经典加密，随后通过纠错码进行编码。码字的每一位通过生成相干态映射至连续变量模式，该相干态在q或p正交方向上被压缩，并施加微小位移以编码比特信息。压缩方向构成加密密钥的一部分。我们基于Broadbent与Lord提出的框架，通过将克隆攻击博弈归约为连续变量纠缠独占性博弈，证明了方案的不可克隆性。此外，我们论证了该方案可利用现有技术直接实现。通过纳入信道噪声与探测器效率等实际缺陷因素，我们证明该协议在这些条件下仍保持鲁棒性。