Toshiba achieved a quantum key distribution rate of 10Mbps over optical fiber, beating their own previous record of 1.9Mbps. The system sends a modulated photon to a remote receiver, which then generates a key based on the randomized photon. This setup allegedly makes QKD invulnerable to any known method of attack or interception. Alan Woodward, a UK computer scientist, said that “Toshiba’s announcement is notable not so much for the speed achieved, as the fact that it appears to have been done over an extended period over already-installed fibers.” Toshiba already announced a system intended to extend the transmission distance from 7km to 500km, by sending photons to both ends of the connection from a central location. Though Toshiba still faces a number of challenges, such as multiplexing the data itself with the key instead of sending it over a separate line, they hope the technology will be ready for commercialization by 2020.



In addition to running these tests, Toshiba and ToMMo operated a wireless sensor network to continuously monitor the installed fiber optic lines using multi-sensor devices incorporating accelerometers and temperature sensors. The aim was to study how the fiber’s characteristics change with shifts in the weather and nearby vibrations, and how such changes impact the performance of the high-speed QKD. Such an understanding is crucial when the technology is applied to existing communication installations, especially where the fiber is aerial and exposed to the elements. “The monitoring has confirmed the correlation between the stability of the high-speed QKD system and disturbances to the installed fiber,” says Tanizawa. “For example, we found wind-induced vibrations in the fiber affected stability. We are now working on improving the stability of the QKD system.”

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Source: [H]ardOCP – Toshiba Pushes 10Mbps of Quantum Key Distribution Through Fiber