Brandão Fernando G S L, Ramanathan Ravishankar, Grudka Andrzej, Horodecki Karol, Horodecki Michał, Horodecki Paweł, Szarek Tomasz, Wojewódka Hanna
Quantum Architectures and Computation Group, Microsoft Research, Redmond, Washington 98052, USA.
Department of Computer Science, University College London, WC1E 6BT London, UK.
Nat Commun. 2016 Apr 21;7:11345. doi: 10.1038/ncomms11345.
Randomness is a fundamental concept, with implications from security of modern data systems, to fundamental laws of nature and even the philosophy of science. Randomness is called certified if it describes events that cannot be pre-determined by an external adversary. It is known that weak certified randomness can be amplified to nearly ideal randomness using quantum-mechanical systems. However, so far, it was unclear whether randomness amplification is a realistic task, as the existing proposals either do not tolerate noise or require an unbounded number of different devices. Here we provide an error-tolerant protocol using a finite number of devices for amplifying arbitrary weak randomness into nearly perfect random bits, which are secure against a no-signalling adversary. The correctness of the protocol is assessed by violating a Bell inequality, with the degree of violation determining the noise tolerance threshold. An experimental realization of the protocol is within reach of current technology.
随机性是一个基本概念，其影响范围涵盖现代数据系统的安全性、自然基本定律乃至科学哲学。如果随机性描述的是外部对手无法预先确定的事件，那么它就被称为经过认证的随机性。众所周知，利用量子力学系统，弱认证随机性可以被放大到近乎理想的随机性。然而，到目前为止，尚不清楚随机性放大是否是一项现实可行的任务，因为现有的方案要么无法容忍噪声，要么需要无限数量的不同设备。在此，我们提供一种容错协议，该协议使用有限数量的设备将任意弱随机性放大为近乎完美的随机比特，这些随机比特对非信号对手具有安全性。该协议的正确性通过违反贝尔不等式来评估，违反程度决定了噪声容忍阈值。该协议的实验实现目前的技术即可达成。
