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.