Moving plane exchanges quantum keys with Earth
September 17, 2012
An airplane has beamed quantum encryption keys to a station on the ground, paving the way for an ultra-secure global communications network, New Scientist reports.
Quantum key distribution (QKD) uses photons polarized in two different ways to encode the1′s and 0′s of an encryption key.
Quantum keys had previously been exchanged between two land-based stations. Now Sebastian Nauerth at the Ludwig Maximilian University of Munich, Germany, and colleagues have extended the feat to an aircraft, a stepping stone to QKD via satellite, which could allow secure messages to be transmitted around the world.
Flying at a speed of nearly 300 km per hour, the challenge was to tightly align the infrared laser pulses transmitted by the aircraft with the receiving station on the ground over a distance of 20 km.