Putting Command, Control, Communications Permanently Out Of Peasant Reach...,

ieee |  Chinese researchers have put forward a new quantum cryptography standard that could, if confirmed, substantially increase the speed of encrypted messages. The proposed new standard has been simulated on computers although not yet tested in the lab.

Quantum cryptography, the next-generation of secret messages whose secrecy is guaranteed by the laws of quantum mechanics, has been in the news recently. Last fall a group from the Chinese Academy of Sciences transmitted quantum cryptographically encoded communications (via satellite) to a ground station in Vienna, Austria.

The communications included quantum-encoded images and a 75-minute quantum-cryptographically secured videoconference, consisting of more than 2 gigabytes of data. IEEE Spectrum reported on the event at the time. And now, as of last month, the entire project has been detailed in the journal Physical Review Letters.

Media coverage of the event stressed its significance in moving toward a so-called “quantum Internet.” Yet the quantum internet would still be a distant dream when quantum cryptography can only mediate one or, at most, a few quantum-secured communications channels. To scale up to anything worthy of the name quantum Internet, quantum cryptography would need to generate not only thousands of cryptographic keys per second. Rather, a scalable quantum crypto system should aspire to key-generation rates closer to billions per second or greater—in the gigahertz (GHz) range and up, not kilohertz (kHz).

cosmos |  For a few minutes each night in certain parts of China, the brightest light in the sky is the lurid glow of the Micius satellite, shooting a green laser down to Earth as it swings through space 500 kilometres above. When conditions are right, you might also see a red beam lancing back through the darkness from one of the ground stations that send signals in reply. 

Micius is not your average telecommunications satellite. On 29 September 2017, it made history by accomplishing an astonishing feat, harnessing the mysterious qualities of quantum entanglement – what Einstein called ‘spooky action at a distance’ – to ‘teleport’ information into space and back again. In doing so, it enabled the first intercontinental phone call – a video call, in fact, between Beijing and Vienna – that was completely unhackable.

The weird science of quantum physics that powers Micius is at the heart of a technology arms race. On one side are quantum computers, still in their infancy but with enormous potential once they grow in power. Among their most prized, and feared, applications is the capacity to cut through the complex mathematical locks that now secure computer encryption systems – the ones that mean you can confidently conduct financial transactions over the internet. On the other side is the only sure defence – encryption techniques that also rely on the laws of quantum physics.

Until recently scientists had managed to make quantum encryption work only across distances of a hundred kilometres or so. The Chinese scientists behind Micius have now reached around the world. It brings the ultimate prize tantalisingly closer. “I envision a space-ground integrated quantum internet,” says Pan Jianwei, whose team became frontrunners in the quantum communications race after Micius switched on.