CESNET successfully transmits precise time and frequency in parallel with quantum keys (QKD)

Prague, April 28, 2022. CESNET has announced the successful cross-border transmission of very precise time and frequency, which was implemented on the link between Ostrava and Těšín in Poland, in parallel with testing of encrypted communication using quantum key distribution (QKD). This first national as well as international intercity QKD transmission, which was carried out on the territory of the Czech Republic, was launched in July last year. Two members of the e-INFRA CZ consortium – the CESNET association and the national supercomputing centre IT4Innovations – and the Polish academic network PSNC are working together.

Parallel transmissions bring significant fibre savings because otherwise three separate lines would be necessary to operate: for regular data transmission, for time and frequency transmission and for QKD transmission. By running everything within one line, there are significant economic savings. In addition, extra physical security for the transmission route against tampering or eavesdropping can be efficiently deployed (see CESNET’s earlier press release here).

“We are still in the testing phase, so we are currently focusing on verifying individual parameters in cooperation with our Polish colleagues. We are using the White Rabbit solution based on the open hardware project originating from CERN with the plan to compare national coordinated national time scaless (UTCs). CESNET has been comparing UTC between Prague and Vienna using cross-border fibre since 2011, which represents the longest-running international transmission of very precise time that is still in operation,” says Josef Vojtěch from CESNET.

The main benefit of the experiment lies in the aforementioned line sharing. As the latest scientific result shoe (e.g. published in Nature.com here), the performance parameters of QKD (range or speed of key transmission) can be advantageously improved by using the supply of very precise time and/or stable optical frequency.

“QKD allows to secure transfer a key for symmetric cryptography between two locations, key is random and it changes during transmission for added security. Precise timing increases the number of sucesfully recived bits in the key, making its changea faster and reducing the risk of the transmission being decrypted,” explains Rudolf Vohnout of CESNET.
Communication encrypted through quantum key exchange represents a new shift in security and addresses the risks associated with the development of quantum computing, which brings with it the real danger of making existing asymmetric encryption methods easier to break. The aforementioned quantum channel between Ostrava and Těšín was built on a 75-kilometre fibre-optic route and achieved a transmission rate of around 2,000 key bits per second.

The implementation was carried out within the European project OpenQKD, in which IT4Innovations National Supercomputing Centre participates. The European Commission has granted the OpenQKD project consortium €15 million to create a quantum network testbed with various use cases.

CESNET works closely with its members in the field of quantum internet. For example, it has long been working with the Brno University of Technology and the Technical University of Ostrava on network security in the so-called post-quantum era, for example, in the framework of the Czech Ministry of the Interior’s project Network Cybersecurity in Post-Quantum Era (NESPOQ – VJ01010008), sponsored by the expert guarantor NÚKIB. In the field of quantum interconnection of ultrastable optical frequency sources, there is also a long-term cooperation with the Institute of Instrumentation of the Academy of Sciences in Brno and Palacký University in Olomouc.

As part of the ongoing upgrade of its network, CESNET is ready to implement dedicated channels for advanced transmissions, including quantum ones on fibre infrastructure, including their assembly abroad and interconnection to international infrastructures. It thus forms the basis of the quantum network in the Czech Republic.

CESNET was founded in 1996 by universities and the Czech Academy of Sciences. It is engaged in research and development of information and communication technologies, building and developing a national CESNET e-infrastructure for research and education. Thanks to its research activities and achievements, it represents the Czech Republic in important international projects, especially in building the pan-European network GÉANT or grid projects (EGI.eu), and participates actively in their implementation. The association is also working on the use of high-speed networks for sharing multimedia data, both synchronously in the form of video conferencing and shared applications, and asynchronously in the form of streaming. Since December 2020, CESNET represents the Czech Republic in the international association dealing with the open science paradigm – EOSC AISBL.Více na: www.cesnet.cz