Diamonds are a hacker's worst friend

A Melbourne University research team has developed technology that will ultimately make it impossible to eavesdrop on communications and steal information - and it all depends on growing diamonds in a microwave oven.

This technology could represent a boon for the financial institutions, security agencies, governments and individuals who need to communicate sensitive information with total security, says Dr James Rabeau, in the School of Physics.

Most information these days is sent via fibre optics. Sending such information from A to B with absolute, uncrackable security depends on the unique properties of light, says Dr Rabeau.

With light beams made up of billions of particles, known as photons, it is possible to divert or tap off some of the photons and reconstruct the information they represent.

But if the information was carried by a stream of single photons, then removing any would both corrupt the information and break the communication thread. The eavesdropper would end up with no useful information, and the sender and receiver would instantly know they were being bugged.

"The biggest limitation confronting this technology has been the lack of a cheap and reliable light source with the adaptations necessary to produce the single-photon light beam," Dr Rabeau says. And that's the problem his team has solved.

The invention involves souped-up microwave oven technology to grow tiny diamond particles onto the tips of optical fibres. The result is a device which generates the critical single light particles.

Two companies are making and selling the equipment necessary for this type of cryptography but the light sources they use are inadequate. This diamond device is the frontrunner to replace the existing sources.

Rabeau and his colleagues recently received a $3.3 million innovation grant from the Victorian government to develop a prototype device and commercialise the technology.