Certified random-number generation from quantum steering

The use of simple quantum processes promises to provide numbers that no physical observer could pre-dict, but in practice, unwanted noise and imperfect devices can compromise fundamental randomness and protocol security. The ultimate random number generators take advantage of quantum nonlocality to certify unpredictability-including to an adversary-even in the absence of trust in devices. We demonstrate a generator of public or private randomness based on the quantum steering task. We use polarization-entangled photon pairs to certify and extract randomness in a one-sided device-independent framework, with the detection loophole closed. Our work enables nonlocality-based certified randomness generation in environmental regimes where fully-device-independent protocols are not feasible.