The first photon gun capable of firing single particles of light over optical fibers was unveiled on Tuesday.

Since quantum encryption works only if the key is sent using individual photons, the breakthrough may remove one of the final obstacles keeping perfectly secure messages from being sent over standard telephone fibers.

Researchers at Toshiba’s Cambridge Research Laboratory in the UK have developed a light-emitting diode that produces up to 1000 single photons per second, allowing a data transfer rate of 1 megabits per second.