China has sent an “unbreakable” code from a satellite to the Earth, marking the first time space-to-ground quantum key distribution technology has been realized, state media said on Thursday.
China launched the world’s first quantum satellite last August, to help establish “hack proof” communications, a development the Pentagon has called a “notable advance”.
The official Xinhua news agency said the latest experiment was published in the journal Nature on Thursday, where reviewers called it a “milestone”.
The satellite sent quantum keys to ground stations in China between 645 km (400 miles) and 1,200 km (745 miles) away at a transmission rate up to 20 orders of magnitude more efficient than an optical fiber, Xinhua cited Pan Jianwei, lead scientist on the experiment from the state-run Chinese Academy of Sciences, as saying.
“That, for instance, can meet the demand of making an absolute safe phone call or transmitting a large amount of bank data,” Pan said.
Any attempt to eavesdrop on the quantum channel would introduce detectable disturbances to the system, Pan said.
“Once intercepted or measured, the quantum state of the key will change, and the information being intercepted will self-destruct,” Xinhua said.
Bottom line: The Chinese are behind the U.S. and Russia in space technology but steps like this one are significant and demonstrate that President Xi Jinping’s quest to prioritize advancement of the country’s space program appears to be paying off. It should also be noted that while most Chinese weapons and armaments are at least a generation behind U.S. and Russian systems, the Chinese space program is one of the country’s “pockets of excellence.”