Free space quantum cryptography with compact modules
H. Weier, T. Schmitt-Manderbach, Patrick Zarda, M. Halder, Christian Kurtsiefer, Harald Weinfurter, P.M. Gorman, P. R. Tapster, John Rarity · 2004
The paper reports on a free space quantum cryptography experiment over a distance of 24.3 km using a BB84 protocol between the summits of two mountains. The obtained bit error rates in this experiment using faint coherent pulses with an average photon number ranging from 0.1 to 0.7 was measured to range from 3 to 5 percent for experiments carried out during night, leading to raw key rates (before error correction and privacy amplification) of 1500 bits per second.