Quantum-secured data transmission in urban fibre-optic communication lines

TL;DR

This paper demonstrates the practical implementation of quantum key distribution over urban fiber-optic lines in Moscow, enabling quantum-secured data transmission for banking infrastructure using the BB84 protocol.

Contribution

It presents a real-world deployment of QKD in existing urban fiber networks, integrating quantum security into standard communication infrastructure for the first time.

Findings

Successful implementation of QKD over urban fiber with significant losses

Continuous key renewal for secure VPN tunnels between bank offices

Potential for long-term quantum-secured data protection

Abstract

Quantum key distribution (QKD) provides theoretic information security in communications based on the laws of quantum physics. In this work, we report an implementation of quantum-secured data transmission in the infrastructure of Sberbank of Russia in standard communication lines in Moscow. The experiment is realized on the basis of already deployed urban fiber-optics communication channels with significant losses. We realize the decoy-state BB84 QKD protocol using the one-way scheme with polarization encoding for generating keys. Quantum-generated keys are then used for continuous key renewal in the hardware devices for establishing a quantum-secured VPN Tunnel between two offices of Sberbank. The hybrid approach used offers possibilities for long-term protection of the transmitted data; it is promising for integrating into the already existing information security infrastructure.