Encrypted messages may soon be more secure thanks to diamonds cooked in a microwave oven, and fused onto optical fibres.
“Even though our information might be pretty secure right now, in 20 years time a quantum computer could crack the code and the information might be still sensitive,” explains Dr James Rabeau, from the University of Melbourne.
Most high speed communication networks use light particles, made up of millions of photons, to transfer information. But even encrypted messages sent this way are not secure because people can tap into the fibres and get unauthorised access to the information.
“When you’re send trillions of photons no one knows the difference between 50 or 100 or 1000 missing,” says Rabeau. This is where ‘quantum cryptography’, which involves using single light particles to encode information, comes in. “If somebody ever tried to take one of these photons they would not get any useful information and immediately the communicating parties would know about this information theft.”
But no one has found a way of producing single particles of light reliably and efficiently at room temperature.
Dr Rabeau set about trying to build a device that would deliver single photons from diamonds into an optical fibre. He used a process which takes place in a kind of microwave oven, to deposit diamond crystals at one end of an optical fibre.
When a laser hits the diamond encrusted tip of the optical fibre, single photons are generated and then sent down the optical fibre as part of a message.