July 2, 2009

Europe builds largest quantum key network

European scientists say they have built the world's largest quantum key distribution network to transmit secure quantum encrypted information.

Officials said 41 research and industrial organizations constructed the eight-node, mesh network consisting of an average 12-mile to 19-mile link, with the longest link being 51 miles. The scientists said their achievement is a huge step toward practical implementation of secure quantum-encrypted communication networks.

The Institute of Physics in London, which announced the accomplishment, said quantum cryptography uses the quantum mechanical behavior of photons -- fundamental particles of light -- to enable highly secure transmission of data beyond that achievable by classical methods.

The photons themselves are used to distribute cryptographic keys to access encrypted information along existing communication lines made of fiber optics, officials said. Quantum indeterminacy, the quantum mechanics dictum that states measuring an unknown quantum state will change it, means the information cannot be accessed by a third party without corrupting it beyond recovery and therefore making the act of hacking futile, the scientists added.

In our paper we have put forward, for the first time, a systematic design that allows unrestricted scalability and interoperability of (quantum key distribution) technologies, the scientists said.

The paper describing the research appears in the New Journal of Physics.