Quantum cryptography is based on the usage of individual particles/waves of light (photon) and their intrinsic quantum properties to develop an unbreakable cryptosystem – essentially because it is impossible to measure the quantum state of any system without disturbing that system. It is theoretically possible that other particles could be used, but photons offer all the necessary qualities needed, their behavior is comparatively well-understood, and they are the information carriers in optical fiber cables, the most promising medium for extremely high-bandwidth communications.
Quantum cryptography in China
At present, China’s WAN Quantum Communication Network Plan has already begun. As the only team in China carrying out space quantum communication research, Pan Jianwei’s team takes the lead to organize the Institute of Strategic Organization pilot project “quantum science experimental satellite” according to which the satellite is scheduled to be launched in 2016 or so. On this basis China is building up its high-speed satellite-ground quantum communication which will be further developed into wide-area quantum network system.
In 2005, the Chinese team for the first time in the world achieved a 13 km free-space quantum communication experiment which confirmed the feasibility of satellite-ground of quantum communication;
In 2012, the Chinese team completed one hundred kilometers free-space quantum teleportation and entanglement distribution experiment in the Qinghai Lake;
In 2013, the first successful full range verification of the satellite-ground quantum key distribution, which laid a solid technical foundation for the realization of global quantum communication.
Backbone quantum communication network will be put into use in three years
Pan Jianwei pointed out that, at present, China’s metropolitan quantum cryptography communication technology is basically matureed, application of which can be pushed forward; inter-city fiber quantum communication network linking Beijing and Shanghai under backbone quantum communication project “Beijing-Shanghai Route” has been officially started, and it is expected to be put into use within two to three years.
Source: People’s Daily, techtarget.com