New method for quantum cryptography developed

A Japanese research group says it has successfully developed the world's first digital signal-processing method that can help create lower-cost and smaller devices for quantum cryptography communication.

Experts say quantum cryptography is theoretically unbreakable. They say it will be necessary as conventional encryption standards could be easily broken with quantum computers that have a much higher level of performance than that of supercomputers.

The current quantum cryptography technology in practical use utilizes photons to carry signals. Photons are microscopic particles of light. Sending photons to carry signals requires expensive apparatus that can keep the environment for the technology at freezing temperatures.

A University of Tokyo research team developed a communication method that does not rely on photons. The method processes signals using a special mathematical function to allow them to pass through optical fiber. It says the technology is as secure as the currently used one.

Koashi Masato, a professor at the University of Tokyo and a member of the research group, says the new method will make it possible to develop a lower-cost and smaller device for quantum cryptography.

The research was published in the Wednesday issue of the British science journal, Nature Communications.