A quantum communication network that successfully connected the Communist Party of China and the government bodies of Jinan will be put into commercial use by the end of August, Chinese state media reported.

The network has passed more than 50 tests in Jinan, capital of east China's Shandong province. The tests had the network transmit data with quantum encryption keys among terminals "spread across several hundred square kilometres" in the city, researchers at the Jinan Institute of Quantum Technology told state-run* Xinhua* news agency.

Zhou Fei, an assistant director at the institute, said the initial quantum network roll-out in Jinan will be restricted to some 200 users, mostly those working in the government, military, finance and electricity sectors.

The system, which uses particles of light to encrypt information, can be used to establish unhackable communications because the said particles can change characteristics in case a third party tries to intercept the information.

The Jinan network is described as an "exclusive" system focusing on quantum communications, according to the report, noting that the information exchange is protected by more than 4,000 qubits per second to achieve "absolute secrecy."