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.
@article{arxiv.1410.3443,
title = {Quantum randomness protected against detection loophole attacks},
author = {Piotr Mironowicz and Gustavo Cañas and Jaime Cariñe and Esteban S. Gómez and Johanna F. Barra and Adán Cabello and Guilherme B. Xavier and Gustavo Lima and Marcin Pawłowski},
journal= {arXiv preprint arXiv:1410.3443},
year = {2021}
}