biostudies-literatureUnknown607(7920)Zhang WDevice-independent quantum key distribution (DIQKD) enables the generation of secret keys over an untrusted channel using uncharacterized and potentially untrusted devices^1-9. The proper and secure functioning of the devices can be certified by a statistical test using a Bell inequality^10-12. This test originates from the foundations of quantum physics and also ensures robustness against implementation loopholes¹³, thereby leaving only the integrity of the users' locations to be guaranteed by other means. The realization of DIQKD, however, is extremely challenging-mainly because it is difficult to establish high-quality entangled states between two remote locations with high detection efficiency. Here we present an experimental system that enables for DIQKDNature687-691https://www.ebi.ac.uk/biostudies/studies/S-EPMC9329124biostudies-literatureA device-independent quantum key distribution system for distant users.PMC9329124Zhang WEppelt SRedeker KFertig FScarani VSchwonnek RWeinfurter HRosenfeld Wvan Leent TLim CCGarthoff RfalseA device-independent quantum key distribution system for distant users.Device-independent quantum key distribution (DIQKD) enables the generation of secret keys over an untrusted channel using uncharacterized and potentially untrusted devices^1-9. The proper and secure functioning of the devices can be certified by a statistical test using a Bell inequality^10-12. This test originates from the foundations of quantum physics and also ensures robustness against implementation loopholes¹³, thereby leaving only the integrity of the users' locations to be guaranteed by other means. The realization of DIQKD, however, is extremely challenging-mainly because it is difficult to establish high-quality entangled states between two remote locations with high detection efficiency. Here we present an experimental system that enables for DIQKD2022-01-01T00:00:00Z2022 Jul2025-04-19T22:58:08.468Z2025-04-19T22:58:08.468ZS-EPMC93291243589665010.1038/s41586-022-04891-y