Quantum randomness protected against detection loophole attacks
  Device and semi-device independent quantum randomness generators (DI- and SDI-QRNGs) are crucial for applications requiring private randomness. However, they are vulnerable to detection inefficiency attacks and this limits severely their usage for practical purposes. Here, we present a method for protecting SDI-QRNGs in prepare-and-measure scenarios against detection inefficiency attacks. The key idea is the introduction of a blocking device that adds failures in the communication between the preparation and measurement devices. We prove that, for any detection efficiency, there is a blocking rate that provides protection against these attacks. We experimentally demonstrate the generation of private randomness using weak coherent states and standard avalanche photo-detectors. 
Piotr Mironowicz, Gustavo Ca\~nas, Jaime Cari\~ne, Esteban S. G\'omez,   Johanna F. Barra, Ad\'an Cabello, Guilherme B. Xavi...
quant-ph