The portable ground station for sending and receiving secure quantum communications, say the researchers, was successfully connected to China’s Quantum Science Satellite - nicknamed Mozi - which was launched in August 2016. The researchers used the mobile station along with a 28-cm (11-inch) telescope to send a secure data transmission using quantum key distribution (QKD) from Jinan in northeast China.
QKD enables two parties to produce and share a random secret key - known only to them - that can be used to encrypt and decrypt information, and with which any attempt by a third party to gain knowledge of the key will be detected. A key was relayed via Mozi between the mobile ground station in Jinan and a fixed station in Shanghai.
The mobile ground station transmits data at a rate of between 4000 and 10,000 bits per second, say the researchers, compared with about 40,000 bits per second for larger stations.
The researchers say they plan to launch a quantum nanosatellite in the next two years, targeted at commercial clients. "We want more and more users to use quantum keys to protect their important information,” says Ji-Gang Ren at the University of Science and Technology of China.