Randomness is a fascinating concept that attracts the interest of multiple thinkers, from philosophers, to mathematicians, physicists, computer scientists and engineers. From a fundamental perspective, the question of whether random processes exist is essential for our understanding of nature. From an applied perspective, randomness is a valuable resource for cryptography, algorithms and simulations. Standard methods for generating randomness, including the current quantum solutions, rely on strong assumptions on the devices that are difficult to meet in practice. However, quantum correlations violating a Bell inequality allow for completely new methods for generating certified randomness. These methods are known as device-independent because they don’t require any modelling of the inner working of the devices. Moreover, they are intrinsically quantum, as no classical system can violate a Bell inequality. Device-independent quantum random-number generators protocols represent a change of paradigm for randomness that solve fundamental and practical drawbacks of standard schemes. The article reviews the efforts and the theoretical and experimental challenges to design deviceindependent randomness generation protocols. Generators with unprecedented standards of quality and security seem within reach using quantum technologies.
Reference
Acín A & Masanes L 2016, ‘Certified randomness in quantum physics’, Nature, vol. 540, pp. 213-219.
