appConfigEntityId

bodyType

customContents

entityId

entityUuid

isVideo

articlePageQuery

article

articleSchemaContent

content

hooksArticlePageAdvertisementConfigArticle

hooksArticlePageFloatingButtonConfigArticle

appConfig

filter

json

liveArticle

SCMP Reporter

The device resting comfortably in  Guo Guangcan's hands may have an unassuming name - it is  called a quantum router - but the Chinese Academy of Sciences member says it has the potential to make military and civilian communication systems  impregnable.

The device brings quantum science and  the internet  infrastructure together to transport encrypted messages which, according to quantum theory, cannot be intercepted or decoded  by a third party. But Hong Kong professor Liu Renbao says the technology is impractical and highly unlikely to have any commercial significance, at least for a century.

The mainland media have declared the equipment to be the first quantum router in the world.  Professor Guo and his team at the National Quantum Communication and Quantum Information Technology Programme say they have succeeded in using it to encrypt data flowing between four computers on a commercial communications system.

Their method uses photons - one of the various quantum forms - to generate and transport keys to unlock encrypted data, replacing the need to send keys through more conventional but unreliable means such as telephone lines.

'Any attempt to detect or steal the photon keys during their transmission will seriously alter their attributes and corrupt the quantum flow, making the system 100 per cent secure in theory,' Professor Guo said.  All encryption methods in use today were potentially vulnerable, he said, because they depended on mathematical complexity - which could be broken by  a fast enough computer.

Developers in some other countries   have carried out point-to-point experiments,  but the mainland  is the first to produce a router,  making a quantum encryption network possible, according to Professor Guo.

He said the military was a key backer of his research and would adopt and improve the router and its related technology before commercial use became possible. One of the technology's problems is that it is only effective over a distance of less than 50km.  'There is still a lot of work to do,' he said.

But Professor Liu, of Chinese University of Hong Kong's physics department, questioned the router's commercial significance.  Existing communication cryptography was mature and safe, and he could see no chance of quantum encryption finding a place in the market, he said.

To compete with existing technologies, quantum communication not only has to have a higher level of security but also be effective over a longer distance and faster bandwidth, he said.

'I think the public should realise that it could still be 100  years before the quantum age, if that age occurs at all,' Professor Liu said.



Quantum leap claimed in tighter internet security