Adding noise for completely secure communication

Science Daily  June 11, 2020
Device-independent quantum key distribution provides security even when the equipment used to communicate over the quantum channel is largely uncharacterized. A central obstacle in photonic implementations is that the global detection efficiency, i.e., the probability that the signals sent over the quantum channel are successfully received, must be above a certain threshold. Researchers in Switzerland developed a protocol that adds artificial noise, which cannot be known or controlled by an adversary, to the initial measurement data (the raw key). Focusing on a realistic photonic setup using a source based on spontaneous parametric down conversion, they gave explicit bounds on the minimal required global detection efficiency and maintained device-independent security…read more. TECHNICAL ARTICLE