China satellite sends 'unbreakable' code

This article is more than 12 months old

Aug 11, 2017 06:00 am

BEIJING: China has sent an "unbreakable" code from a satellite to Earth, marking the first time space-to-ground quantum key distribution technology has been realised, state media said yesterday.

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 experiment was published in the journal Nature, with reviewers calling it a "milestone".

The satellite sent quantum keys to ground stations in China from 645km to 1,200km away at a transmission rate up to 20 orders of magnitude more efficient than optical fibre, Xinhua cited the experiment's lead scientist Pan Jianwei as saying.

"That, for instance, can meet the demand of making an absolute safe phone call or transmitting a large amount of bank data," he said.

Any attempt to eavesdrop on the quantum channel would introduce detectable disturbances to the system, added Mr Pan.