The government is putting its weight behind quantum cryptography as a key way of making communications hack-proof.

The Department of Trade and Industry (DTI) and the emerging technologies division of the e-Envoy's office have unveiled a project to investigate and encourage developments in the technology.

Speaking at the National Hi-Tech Crime Unit's second e-Crime Congress last week, Bernard Frieder, the e-Envoy's director of emerging technologies, told delegates that quantum cryptography could change the way business is done.

"Quantum cryptography is an entirely new way of looking at security: it is immune to hacking," he said.

Frieder called for firms developing the technology to participate in the DTI trials so that the Royal Society and its chief scientists could evaluate claims, assertions and viability.

"We will be coming out with a report at the end the trials looking at the state of the market," he added.

Quantum cryptography uses tamper-proof photon light particles to encode each transmitted bit, guaranteeing security over an optical network.

Because the particle is so delicate, if anyone tries to spy on the encrypted data as it travels down the fibre optic cables its encoding will change.

In such a case both sender and recipient would immediately be alerted to the potential hack, with users warned not to use the encryption key again.

"You don't have to worry whether someone has tapped into your network; it will tell you," said Frieder.

The technology will have its biggest benefits in large organisations such as banks and government departments, which need to guarantee highly secure links between local sites.

But Professor Neil Barrett, technical director of security consultancy Information Risk Management, said it would be at least five to 10 years before quantum cryptography became commercially viable.

"It's not going to replace Secure Sockets Layer in a hurry; it's still a long way away before it becomes practical," he said.

"The technology needs to be simplified. As well as particles being sensitive to tampering at the moment they can also be affected by interference."

Barrett added that the technology was also restricted by only being capable of working point-to-point on an optical fibre network, meaning that until there are technological advancements it can only be used over shorter distances.