Free-space Quantum Key Distribution over 10 km in Daylight and at Night

Sheng‐Kai Liao, Hai-Lin Yong, Chang Liu +22 more

David M. Benton, Phillip M. Gorman, Paul R. Tapster +1 more

Heasin Ko, Chun Ju Youn

Richard Hughes, J. E. Nordholt, George L. Morgan +1 more

We have demonstrated quantum key distribution (QKD) over a 10-km, 1-airmass atmospheric range during daylight and at night. Secret random bit sequences of the quality required for the cryptographic keys used to initialize secure communications devices were transferred at practical rates with realistic security. We infer from these results that free-space QKD will be practical over much longer ranges under these and other atmospheric and instrumental conditions.

Richard Hughes, J. E. Nordholt, Derek Derkacs +1 more

We have demonstrated quantum key distribution (QKD) (Bennett C H and Brassard G 1984 Proc. IEEE Int. Conf. on Computers, Systems, and Signal Processing (Bangalore, India) p 175) over a 10 km, 1-airmass atmospheric range during daylight and at night. Secret random bit sequences of the quality required for the cryptographic keys used to initialize secure communications devices were transferred at practical rates with realistic security. By identifying the physical parameters that determine the system's secrecy efficiency, we infer that free-space QKD will be practical over much longer ranges under these and other atmospheric and instrumental conditions.

Simon Fossier, Jérôme Lodewyck, Eleni Diamanti +4 more