China transmits first ‘unhackable’ message to satellite

Chinese scientists have sent the first quantum transmission from earth to an orbiting satellite, marking another key step in the creation of an “unhackable” global communications network, the Financial Times reports. In a summary of their experiment published on Thursday in the scientific journal Nature, the team led by Pan Jianwei said the transmissions had traveled as far as 1,400km between base stations in central and western China and a satellite launched last year. “Previous [quantum] teleportation experiments between distant locations were limited to a distance of the order of 100km,” the scientists wrote. Unlike traditional communications, which can be tapped surreptitiously, anyone attempting to eavesdrop on a quantum communication creates a disturbance that can be detected by the network’s users. Tim Byrnes, a quantum physicist at New York University’s Shanghai campus, described the result as “truly remarkable.” He noted that before China’s successful experiments the longest distance traveled by a quantum communication had been 143km.