Australian scientists believe they have developed an unbreakable information code to stop hackers, using a diamond, a kitchen microwave oven and an optical fibre. Researchers at Melbourne University used the microwave to "fuse" a tiny diamond, just 1/1000th of a millimetre, onto an optical fibre, which could be used to create a single photon beam of light which they say cannot be hacked. Photons are the smallest known particles of light. Until now, scientists could not produce a single-photon beam, thereby narrowing down the stream of light used to transmit information. Laser beams which are used at the moment send billions of photons, making it easy for hackers to steal some of them and break the code, said Rabeau. The diamond device sends a stream of single photons, so that if the chain of communication is broken, the information becomes corrupted and a hacker immediately exposed to both the sender and the receiver, he said. Only diamonds are known to create single-photon beams.