Abstract: Quantum physics can be exploited to generate true random numbers, which play important roles in many applications, especially in cryptography. Genuine randomness from the measurement of a quantum system reveals the inherent nature of quantumness—coherence, an important feature that differentiates quantum mechanics from classical physics. The generation of genuine randomness is generally considered impossible with only classical means. Based on the degree of trustworthiness on devices, quantum random number generators (QRNGs) can be grouped into three categories. The first category, practical QRNG, is built on fully trusted and calibrated devices and typically can generate randomness at a high speed by properly modeling the devices. The second category is selftesting QRNG, where verifiable randomness can be generated without trusting the actual implementation. The third category, semiselftesting QRNG, is an intermediate category which provides a tradeoff between the trustworthiness on the device and the random number generation speed.

Key words: coherence, quantum random number generator, self-testing, semi-self-testing

摘要： 利用量子物理中的基本原理可以产生真随机数，它们在许多应用尤其是密码学中起到重要作用.对一个量子系统进行测量得到的真随机性揭示了量子特性——相干性，这是一个区分量子力学和经典力学的重要特性.根据对设备的信赖程度，量子随机数发生器可以被分为三大类：第1类是实用化的量子随机数发生器，这类发生器需要充分信任设备并建立适当的物理模型对设备进行描述，通常可以有很高的随机数产生率；第2类是自检测量子随机数发生器，可以在不信任设备的条件下产生随机数；第3类是半自检测量子随机数发生器，它是介于前2类之间的一类方案，通过部分地信任设备来获得相对较高的随机数产生率.

关键词: 量子相干性, 量子随机数发生器, 自检测, 半自检测