Chinese state media reported that researchers at the Jinan Institute of Quantum Technology had successfully completed testing a quantum communication network connecting Communist Party and government bodies in Jinan, capital of east China's Shandong Province. The network is expected to be put into use by the end of next month. The network would enable absolutely secure communications impenetrable to hackers.
The network has passed more than 50 tests. It transmitted data with quantum encryption keys among nearly 200 terminals in the city during the tests. Zhou Fei, an assistant director of the Institute said that between users, more than 4,000 keys were generated in just a second. He aded that the success of the test is a landmark in the development of quantum communication technology worldwide, paving the way for its commercial use first in government and then in finance, energy and other sectors.
According to Global Times, the system can only encrypt text currently. It could eventually be used to encrypt and transmit audio and video files.
Quantum communication uses quantum entanglement of photons to make sure that nobody is able to tap into the communications. Quantum entanglement is a phenomenon when pairs or groups of particles cannot be described independently of the others. The physical properties of the particles are correlated and the correlation persists regardless of the distance separating them.
This is used to establish unhackable communications, as quantum entanglement would ensure that the intrinsically random, shared secret key for encrypting and decrypting messages, can only be deciphered by authorised individuals or entities. If we perform a measurement on one of two entangled objects, the entanglement correlation is broken. If this measurement is done by an eavesdropper then the end-users detect no entanglement, and the eavesdropper is revealed. In this system in Jinan, an error code will be generated and users on the network will be alerted in the event of a security breach.
China has been achieving several world-firsts in the area of quantum communication. In August 2016, China launched the world’s first satellite dedicated to quantum experiments. Using the satellite, in June this year Chinese scientists broke the record for the greatest distance over which quantum entanglement has been achieved. They successfully demonstrated satellite-based entanglement distribution to receiver stations separated by a distance of over 1200 km. The results illustrate the feasibility of using quantum devices on satellites to build a future global quantum communication network.
Last November, Xinhua reported that a 712-km quantum communication line had been opened in east China, making it the world's longest secure quantum telecommunications network in use. The line links Hefei, capital of Anhui Province, to Shanghai and is part of a 2,000-km quantum communication line connecting Beijing and Shanghai.