For the first time the transmission of data secured by quantum cryptography is demonstrated within a commercial telecommunications network. 41 partners from 12 European countries, including academics from the University of Bristol, have worked on realising this quantum cryptographic network since April 2004.
Today [Wednesday 8 October] the first commercial communication network using unbreakable encryption based on quantum cryptography is demonstrated in Vienna, Austria. In particular the encryption utilises keys that are generated and distributed by means of quantum cryptographic technologies. Potential users of this network, such as government agencies, financial institutions or companies with distributed subsidiaries, can encrypt their confidential communication with the highest level of security using the quantum cryptographically generated keys.
The network consists of six nodes and eight intermediary links with distances between 6km and 82km (seven links utilising commercial standard telecommunication optical fibres and one “free-space”-link along a line of sight between two telescopes). The links employ altogether six different quantum cryptographic technologies for key generation which are integrated into the network over standardised interfaces.
The network is installed in a standard optical fibre communication ring provided by SECOQC partners, Siemens AG Österreich in Vienna. Five subsidiaries of Siemens are connected to the network. The operation of the quantum cryptographic network will be visualised on a screen at the Siemens Forum in Vienna and streamed live over the Internet. The network-wide key generation and distribution will be demonstrated, the different functionalities of the network itself will be presented as well as utilisation of the keys for standard communication applications. A voice-over-iptelephone-application will be secured by the information-theoretically secure “one-time-pad-encryption“ while videoconferencing will be protected by symmetrical AES-encryption with frequent key changes. A low-cost key distributor, with the potential of extending the quantum cryptographic network to the consumer, will also be shown.