Quantum breakthrough from Chinese satellite mission could improve communications security

Communications engineers in China are claiming a major breakthrough in security after demonstrating that a property of quantum science can be used to protect encoding of messages over long distances. Using a communications satellite called Micius, the researchers, from the University of Science and Technology of China, have transmitted quantum-entangled photon pairs to sites separated by 1200km: much farther than has ever been demonstrated before, and the first time this technique has been successfully used with space-based communication.

Many types of communication today use sophisticated encryption to keep them secret; most notably, financial information and other commercially- or security- sensitive communications. This cryptography typically uses long numbers as a key to scrambling and unscrambling the data. But as cyber hacking becomes more sophisticated, there are concerns that criminals could intercept and decode communications based on even the most complex numerical cryptography.

Quantum cryptography is an even more sophisticated method of keeping communications private. It relies on "entangled photons": particles of light, which are created simultaneously and have identical properties no matter how far apart they are. Because at the quantum level, observation changes that which is being observed, the act of eavesdropping interferes with the communication itself, indicating that the messages are not secure.