Assuring quantum randomness from simple optical measurements

随机数是科学和技术的基本组成部分，特别是与密码学，游戏，模拟或统计相关。量子随机数生成器（QRNG）依靠量子力学固有的随机性来生成真实的、不可预测的随机数，这是经典物理学无法实现的。证明和量化量子系统输出中的随机性的方法和协议是当前深入研究的课题。本文针对量子随机数生成这一新兴领域，提出了两种半设备无关的获取量子熵的方案，并详细讨论了它们的优缺点。为了开发这些方法的认证协议，我们彻底研究了光电探测器的实现及其可能在我们的方法中引入的漏洞。最后，我们进行了一个概念验证实验，以证明所建议方案的可行性，并实验研究了推导的理论模型的正确性。这些实验的结果显示了与理论的令人满意的一致性，并使我们能够从我们的QRNG中提取出每个样本1.58比特的量子随机性，并进行8位数字化。

Random numbers are a fundamental part of science and technology, being especially relevant forcryptography, gaming, simulations or statistics. Quantum random number generators (QRNG) rely onthe intrinsic randomness of quantum mechanics to generate true and unpredictable random numbers,unachievable from the classical physics perspective. Methods and protocols to certify and quantifythe randomness in the output of a quantum system are a current subject of intensive research. Inthis thesis, we focus on the emergent field of quantum random number generation proposing two semidevice-independent schemes to harvest quantum entropy while discussing in detail their strengths andweaknesses. With the purpose of developing a certification protocol for these approaches, we thoroughlystudy the implementation of the photodetector and the possible vulnerabilities it might introduce inour approaches. Finally, we perform a proof-of-concept experiment to demonstrate the feasibility ofthe suggested schemes and experimentally investigate the correctness of the derived theoretical models.The results for these experiments revealed a satisfactory agreement with the theory and enabled us toextract 1.58 bits of quantum randomness per sample with an 8-bit digitisation out of our QRNG.