The world's first quantum-encrypted government network has been put into trial operation in Wuhu City in the eastern Chinese province of Anhui, Guo Guangcan, a member of Chinese Academy of Sciences (CAS) and researcher of CAS Key Laboratory of Quantum Information, told a press conference in Wuhu on May 18. The new network demonstrates that China is able to put quantum cryptography to practical use, said Guo.

The quantum-encrypted network will serve eight government departments in Wuhu, including the Science & Technology Bureau, the Investment Promotion Bureau and the Economic & Trade Commission. It enables secure communication between any two parties. In addition to secure voice transmission, documents and pictures, it allows secure transmission of video conferences and large sized documents. All key devices used in the network were designed and manufactured domestically.

Quantum cryptography uses quantum mechanics to guarantee secure communication. In the application of quantum cryptography, unstable information transmission via commercial cables is a major problem, and in building a quantum encrypted network, secure information routing is a major technical issue.

In 2004, Guo Guangcan and his teammates invented a new optical-interference device that distributed quantum keys via commercial cables up to 125 km long. In 2007, Guo developed a quantum router that blocked attempts to detect or steal quantum key during data transmission.

(China.org.cn by Chen Xia, May 21, 2009)