Quantum-secure transmission at 100 Gb/s in a live network

CESNET has successfully tested a combination of QKD and post-quantum cryptography on an operational route in Prague.

As part of the NESPOQ project, CESNET staff verified that QKD and PQC can reliably protect data transmissions on a 100 Gb/s operational line within a real network environment. On a 9.1 km route between the CESNET TLH laboratory and Prague's DC Tower, CESNET demonstrated that the IDQ Clavis3 QKD system, when used alongside encryption units developed by the Brno University of Technology (VUT), can ensure secure transmission of demanding multimedia and large volumes of data.

The main objective of the testing was to demonstrate the joint use of the IDQ Clavis3 QKD system as a key security component for protecting data lines with speeds of up to 100 Gb/s, in combination with encryption units designed by the project's co-investigator, the Brno University of Technology.

QKD and post-quantum cryptography in a real metropolitan environment
The total length of the optical route in the urban environment was 9.1 km. Since the quantum channel typically requires a dedicated fibre, the existing data traffic and service channels of the QKD system had to be merged into the second fibre using a filter system. Using the filter system significantly increased the total attenuation of the optical route, meaning that only 1% of the transmitter's optical power reached the receiver. Consequently, Ribbon's high-speed DWDM transmission system was required to implement secure encrypted channel transmission. 

Verification of functionality on standard and multimedia data
A series of tests were conducted in a real environment to verify the functionality of the secure channel when transmitting sensitive data. As well as artificially generated verification traffic, standard types of data transmission were tested, including file transfers and 4K video streaming using the Modular Video Transmission Platform (MVTP). When transferring a compressed 4K video stream via a secure channel, the data flow rate was approximately 220 Mb/s. The entire transfer was completed without error via an encrypted channel, thus verifying the stability of the solution even under a real multimedia load.

'During the tests, the encryptor demonstrated its ability to utilise the full capacity of the 100 Gb/s line when transmitting large data frames. The actual speeds achieved were primarily limited by the performance of the traffic generator used, rather than the encryption system itself," explains Ondřej Havliě fromthe CESNET.

The results are ready for practical deployment
Real-world testing has shown that the combination of QKD and post-quantum cryptography can reliably secure even very fast data transfers. In practice, this means that this technology is ready to protect critical network services, even in environments where high demands are placed on capacity and stability. The combination of QKD and PQC thus represents a robust and practical solution for network applications requiring the highest level of security.

A video is also available, which you can view here: Kvantově zabezpečený přenos na 100 Gb/s v reálné síti