Practical free-space quantum key distribution over 1 km
  A working free-space quantum key distribution (QKD) system has been developed and tested over an outdoor optical path of ~1 km at Los Alamos National Laboratory under nighttime conditions. Results show that QKD can provide secure real-time key distribution between parties who have a need to communicate secretly. Finally, we examine the feasibility of surface to satellite QKD. 
W. T. Buttler, R. J. Hughes, P. G. Kwiat, S. K. Lamoreaux, G. G.   Luther, G. L. Morgan, J. E. Nordholt, C. G. Peterson, and...