(NewElectronics.co.uk) The Chinese satellite Mincus has steadily been extending the reach of an encryption technology that is practically unbreakable.
The Quantum Experiments at Space Scale (QUESS) satellite demonstrated it was possible for photons sharing quantum entanglement to convey data over 750km. By June this year, that distance had increased to 1200km. Before the QUESS experiments began, researchers were unsure as to how far entanglement could be stretched. Now it looks as though satellites could let entangled states straddle continents.
Thus far, China has been leading in the quest to build long-distance networks that use quantum entanglement to improve security rather than classical communications technologies. A year after Micius went into orbit, a consortium of research institutes completed a fibre-based ground network that ran from Beijing to Shanghai through Jinan and Hefei across a distance of almost 2000km. In contrast to the direct communication between satellite and ground stations, the Beijing-Shanghai requires numerous relay stations. But both networks are pointing the way towards a radical change in the way encryption is used.