The highest bit rate system currently demonstrated exchanges secure keys at 1 Mbit/s (over 20 km of optical fibre) and 10 kbit/s (over 100 km of fibre), achieved by a collaboration between the University of Cambridge and Toshiba using the BB84 protocol with decoy pulses[5].

As of March 2007[update] the longest distance over which quantum key distribution has been demonstrated using optic fibre is 148.7 km, achieved by Los Alamos/NIST using the BB84 protocol[6]. Significantly, this distance is long enough for almost all the spans found in today’s fibre networks. The distance record for free space QKD is 144 km between two of the Canary Islands, achieved by a European collaboration using entangled photons (the Ekert scheme) in 2006[7], and using BB84 enhanced with decoy states[8] in 2007 [9]. The experiments suggest transmission to satellites is possible, due to the lower atmospheric density at higher altitudes. For example although the minimum distance from the International Space Station to the ESA Space Debris Telescope is about 400 km, the atmospheric thickness is about an order of magnitude less than in the European experiment, thus yielding less attenuation compared to this experiment.

The DARPA Quantum Network[10], a 10-node quantum cryptography network, has been running since 2004 in Mbumachusetts, USA. It is being developed by BBN Technologies, Harvard University, Boston University and QinetiQ.

There are currently four companies offering commercial quantum cryptography systems; id Quantique (Geneva), MagiQ Technologies (New York), SmartQuantum (France) and Quintessence Labs (Australia). Several other companies also have active research programmes, including Toshiba, HP, IBM, Mitsubishi, NEC and NTT (See External links for direct research links).

Quantum encryption technology provided by the Swiss company Id Quantique was used in the Swiss canton (state) of Geneva to transmit ballot results to the capitol in the national election occurring on Oct. 21, 2007.[10]

In 2004, the world’s first bank transfer using quantum cryptography was carried in Vienna, Austria. An important cheque, which needed absolute security, was transmitted from the Mayor of the city to an Austrian bank.[11]

The world’s first computer network protected by quantum cryptography was implemented in October 2008, at a scientific conference in Vienna. The network used 200 km of standard fibre optic cable to interconnect six locations across Vienna and the town of St Poelten located 69 km to the west. The event was witnessed by Gilles Brbumard and Anton Zeilinger. [11]