Quantum Key Distribution over 67 km with a plug & play system
  We present a fibre-optical quantum key distribution system. It works at 1550nm and is based on the plug & play setup. We tested the stability under field conditions using aerial and terrestrial cables and performed a key exchange over 67 km between Geneva and Lausanne. 
D. Stucki, N. Gisin, O. Guinnard, G. Ribordy, H. Zbinden