Certified randomness in quantum physicsNature has recently published an important review paper entitled ‘Certified randomness in quantum physics’ by ICREA Prof at ICFO Antonio Acín and ICFO Alumnus Dr. Lluis Masanes, currently in the Department of Physics & Astronomy, University College of London.
In this paper, Acín and Masanes discuss randomness, 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. The article reviews the efforts and challenges to design device-independent randomness generation protocols.