China's "Micius" completes intercontinental quantum key distribution

China's quantum satellite "Micius" has allowed scientists to achieve quantum key distribution between China and Austria, laying a foundation for building a global quantum-secured communication network.

The achievement, jointly made by Chinese and Austrian scientists, was published on Jan. 19 in the journal Physical Review Letters. It demonstrates that the Chinese quantum satellite is capable of facilitating intercontinental quantum-secured communications.

Photo taken on Nov. 26, 2016 shows a quantum communication ground station in Xinglong, north China's Hebei Province. [Photo: Xinhua/Jin Liwang]

Through satellite-to-ground secure key distribution, a secret key was created between the two countries at locations some 7,600 km away from each other.

During the experiment, scientists transmitted images between the two countries, and a 75-minute video conference was successfully held between Beijing and Vienna.

Traditional public key cryptography risks being hacked, while quantum key technology, used in quantum communication, eliminates the possibility of wiretapping and secures the communication.

The satellite -- Quantum Experiments at Space Scale (QUESS), nicknamed "Micius" after an ancient Chinese philosopher -- was launched on Aug. 16, 2016.

In 2017, Chinese scientists achieved quantum key distribution from the satellite to the ground, and quantum teleportation from the ground to the satellite, based on experiments with the Micius.