Quantum random number generator (QRNG) can theoretically generate unpredictable random numbers with perfect devices, which is an ideal and secure source of random numbers for cryptography. However, the practical implementations always contain imperfections, which will greatly influence the randomness of the final output and even open loophole to eavesdroppers. Recently, J. Thewes et.al. experimentally demonstrate a continuous-variable eavesdropping attack, based on heterodyne detection, on a trusted continuous-variable QRNG in Phys. Rev. A 100, 052318 (2019), yet like many other practical continuous-variable QRNG researches, they always suppose the local oscillator is stable and ignore its fluctuation which might lead to security threats such as wavelength attack. In this work, based on the theory of the conditional min-entropy, imperfections on the practical security of continuous-variable QRNG are systematically analyzed, especially the local oscillator fluctuation under imbalanced homodyne detection. Experiments of a practical QRNG based on vacuum fluctuation are demonstrated to show the influence of local oscillator fluctuation on the total measurement noise variances and the practical conditional min-entropy with beam splitters of different transmittances. Moreover, a local oscillator monitoring method is proposed for the practical continuous-variable QRNG, which can be used to calibrate the practical conditional min-entropy.

中文翻译：

---

带噪声本地振荡器的连续变量量子随机数发生器的实用安全性分析

量子随机数发生器（QRNG）在理论上可以使用完善的设备生成不可预测的随机数，这是用于加密的理想且安全的随机数源。但是，实际的实现总是包含缺陷，这将极大地影响最终输出的随机性，甚至会给窃听者带来漏洞。最近，J。Thewes等人。实验性地展示了基于外差检测的对Phys中可信赖的连续变量QRNG的连续变量窃听攻击。Rev.A 100，052318（2019），但是像许多其他实用的连续变量QRNG研究一样，他们始终认为本地振荡器是稳定的，并且忽略了其波动，这可能导致诸如波长攻击的安全威胁。在这项工作中，基于条件最小熵的理论，系统分析了连续变量QRNG在实际安全性上的缺陷，尤其是在零差零差检测下的局部振荡波动。演示了基于真空起伏的实际QRNG实验，以显示本地振荡器起伏对总测量噪声方差和使用不同透射率的分束器的实际条件最小熵的影响。此外，针对实际的连续变量QRNG，提出了一种本地振荡器监测方法，可以用来校正实际的条件最小熵。演示了基于真空起伏的实际QRNG实验，以显示本地振荡器起伏对总测量噪声方差和使用不同透射率的分束器的实际条件最小熵的影响。此外，针对实际的连续变量QRNG，提出了一种本地振荡器监测方法，可以用来校正实际的条件最小熵。演示了基于真空起伏的实际QRNG实验，以显示本地振荡器起伏对总测量噪声方差和使用不同透射率的分束器的实际条件最小熵的影响。此外，针对实际的连续变量QRNG，提出了一种本地振荡器监测方法，可以用来校正实际的条件最小熵。