Chinese Researchers break world record for quantum-encrypted communications
(Engadget) Steve Dent reports on Beijing researchers setting a new quantum secure direct communication (QSDC) world record of 102.2 km (64 miles), smashing the previous mark of 18 km (11 miles). IQT-News summarizes.
Transmission speeds were extremely slow at 0.54 bits per second, but still fast enough for text message and phone call encryption over a distance of 30 km (19 miles), wrote research lead Long Guilu in Nature.
The same research team set the previous fiber record, and devised a “novel design of physical system with a new protocol” to achieve the longer distance. They simplified it by eliminating the “complicated active compensation subsystem” used in the previous model. “This enables an ultra-low quantum bit error rate (QBER) and the long-term stability against environmental noises.”
As a result, the system can withstand much more so-called channel loss that makes it impossible to decode encrypted messages. That in turn allowed them to extend the fiber from 28.3km to the record 102.2 km distance. “The experiment shows that intercity quantum secure direct communication through the fiber is feasible with present-day technology,” the team wrote in Nature.
Sandra K. Helsel, Ph.D. has been researching and reporting on frontier technologies since 1990. She has her Ph.D. from the University of Arizona.