Pulsed laser attack at 1061nm potentially compromises quantum key distribution

Applied Physics Letters. 2025. Vol. 127. No. 19. P. 194002.

Ponosova A., Zhluktova I., Ruzhitskaya D., Trefilov D., Huang A., Wolf A., Kamynin V., Tsvetkov V., Makarov V.

Quantum key distribution systems offer cryptographic security, provided that all their components are thoroughly characterized. However, certain components might be vulnerable to laser-damage attacks, particularly when subjected to untested laser parameters. Here, we show that exposing 1550-nm fiber-optic isolators to 1061-nm sub-nanosecond pulsed illumination with 1.16 W average power permanently degrades their isolation performance at 1550 nm, while their forward transparency is less affected. One experimental sample was exposed to 17 mW average power picosecond attacking pulses that temporarily reduced its isolation below the specified guaranteed minimum value. This indicates a potential security threat under these attacking laser regimes that need to be addressed by improving security analysis for various light-injection attacks.

Keywords: квантовая криптография, Quantum key distribution, side-channel attacks, nanosecond laser, уязвимости систем квантовой связи, атака лазерным повреждением, квантовое распределение ключей, quantum cryptography, квантовая криптография, квантовое распределение ключей, детектор-независимое квантовое распределение ключей, КРК с НЦУ, детектор одиночных фотонов, мертвое время, quantum hacking