China holds world’s first secure quantum video conference

China Central Television (CCTV)- Chinese scientists held the world’s first quantum intercontinental communication video conference with their counterparts in the Austrian capital of Vienna on Friday, thanks to the successful connection between China’s quantum communication line and satellite.

The 2,000-kilometer quantum communication line put into use on the same day is the world’s first trunk line for secure quantum telecommunications. Known as the Jing-Hu (Beijing-Shanghai) Trunk Line, it connects the country’s major secret communication network nodes Beijing, Jinan, Hefei and Shanghai.

The line is connected to the world’s first quantum satellite, which was launched by China in August last year, through a station in Beijing. The satellite is nicknamed “Micius”, after a fifth century BCE Chinese philosopher and scientist who has been credited as the first person to conduct optical experiments.

With Micius’ connection to a ground station in Austria, the Chinese scientists were able to have cross-continent communication with quantum physicist Anton Zeilinger and other scientists in Vienna.

Like in traditional transmissions, the video was transmitted on a public network. But as principle scientist of the trunk line, Pan Jianwei, pointed out, the big difference was the advanced encryption method on the quantum communication line.

“The only difference is that the video is encrypted by quantum keys before it is sent back. After the encryption, it is shown as a pile of messy codes on the public network. Once it reaches the receiving terminal, we can decrypt it using the encryption keys,” he said.

The success of connection between the Jing-Hu Trunk Line and the quantum satellite, according to Pan, marks the formation of the prototype of a space-ground integrated quantum network.

“Today, for the first time, we demonstrated that the intercontinental encryption key distribution can be applied in the wide area network. And the satellite’ connection to the optical network proved that our satellites can be accurately matched with the ground network. These facts make up the two foundations for a future space-ground wide area network. In this sense, the prototype of a space-ground integrated quantum network has come into being,” said Pan.

During the exchanges, Bai Chunli, president of the Chinese Academy of Sciences (CAS), said the first real-time call in the continental quantum communication has marked a big day for science and its application.

Zeilinger expressed congratulations on the achievements by Chinese scientists in the field of quantum communication.

Safety of the quantum-communications security technology is decided by the subatomic properties of the photons. Different from conventional data-encryption methods that use 0s and 1s to encrypt and decrypt information, quantum communication allows users to code information into the specific quantum state of photons, the smallest energy unit in this type of communication. As the act of eavesdropping inevitably alters the quantum state, users on both ends of the quantum-communications network will be alerted when there is a security breach,

The high level of protection makes quantum-communications encryption technology ideal for information security in the finance sector, government affairs and other fields.

Chinese businesses, including the Bank of Communications, the Industrial and Commercial Bank of China and Alibaba have used the network.