China takes lead in quantum communication with satellite

THE WORLD'S FIRST quantum communication experimental satellite was successfully launched into space on Tuesday from Jiuquan in Northwest China's Gansu province. Beijing Youth Daily commented:

The Quantum Experiments at Space Scale, or QUESS, satellite is designed to test technology for hack-proof encrypted communications from space to the ground. Although there are fiber-optic quantum key distribution networks already in some countries, including China, this is the first large-scale attempt to use such quantum technology for satellite communications.

Simply speaking, quantum communication makes use of the quantum entanglement phenomenon. The satellite will create pairs of sub-atomic particles whose properties are dependent on one another, beaming one of the paired particles down to a base station on Earth. Theoretically, the information transmitted this way cannot be hacked, as any observation of an encryption key transmitted in this way would change the quantum state, changing the key and rendering it useless.