We present an efficient method to extract the amount of true randomness that can be obtained by a Quantum Random Number Generator (QRNG). By repeating the measurements of a quantum system and by swapping between two mutually unbiased bases, a lower bound of the achievable true randomness can be evaluated. The bound is obtained thanks to the uncertainty principle of complementary measurements applied to min- and max- entropies. We tested our method with two different QRNGs, using a train of qubits or ququart, demonstrating the scalability toward practical applications.
@article{arxiv.1401.7917,
title = {Quantum Randomness Certified by the Uncertainty Principle},
author = {G. Vallone and D. Marangon and M. Tomasin and P. Villoresi},
journal= {arXiv preprint arXiv:1401.7917},
year = {2014}
}