Toshiba may break quantum security distance record.
Toshiba has new way to use the laws of quantum mechanics to send secure messages using current technology. Toshiba claims its new method could set up a secure, quantum communications link over fibers up to 550 kilometers long. Toshiba researchers claim that the two users, Alice and Bob that are miles apart, can each bestow an electric field with a certain quantum state and send it over a fiber optic cable to a central, insecure location, where the two fields would join and undergo quantum interference. Each user would then receive back the result of the single photon that resulted from the interference. This information would be meaningless to an observer but could serve as an unhackable quantum key to decrypt their messages. This is similar to the way researchers sent a quantum key between stations 404 kilometers apart in 2016. The 2016 research required two photons sent over the fiber optic cable, one each from Alice and Bob. Toshiba's research requires only a single photon sent by either Alice or Bob. Sending fewer photons means the researchers could overcome a previous perceived limit to the distance a quantum key could be sent.
The theoretical research was recently published in Nature. Toshiba hopes to demonstrate it controlled, lab experiments in the next year then make a prototype in two years time. Toshiba has been working on distributing quantum keys with existing methods as well. Hoi-Kwong Lo, a professor at the University of Toronto pointed out that it's unclear whether or not the method could overcome cyber attacks with the capabilities of quantum mechanics at their disposal. Quantum key distribution could be useful for sharing secure things like genetic data or government data, and then maybe have more general applications in the future. It's still far off, but many scientists and companies are hoping to see quantum secure networks spanning the world.