Quantum randomness protected against detection loophole attacks

Device and semi-device independent quantum randomness generators (DI- SDI-QRNGs) are crucial for applications requiring private randomness. However, they vulnerable to detection inefficiency attacks this limits severely their usage practical purposes. Here, we present a method protecting SDI-QRNGs in prepare-and-measure scenarios against attacks. The key idea is the introduction of blocking device that adds failures communication between preparation measurement devices. We prove that, any efficiency, there rate provides protection these experimentally demonstrate generation using weak coherent states standard avalanche photo-detectors.