Quantum randomness protected against detection loophole attacks

• Published in: Quantum information processing Vol. 20; no. 1
• Main Authors: Mironowicz, Piotr, Cañas, Gustavo, Cariñe, Jaime, Gómez, Esteban S., Barra, Johanna F., Cabello, Adán, Xavier, Guilherme B., Lima, Gustavo, Pawłowski, Marcin
• Format: Journal Article
• Language: English
• Published: New York Springer US 2021; Springer Nature B.V
• Subjects: Data Structures and Information Theory; Generators; Mathematical Physics; Measuring instruments; Physics; Physics and Astronomy; Quantum Computing; Quantum Information Technology; Quantum Physics; Randomness; Spintronics; Quantum random number generation; Detection efficiency
• ISSN: 1570-0755; 1573-1332; 1573-1332
• DOI: 10.1007/s11128-020-02948-3

Device and semi-device-independent private quantum randomness generators 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 semi-device-independent private quantum randomness generators 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.