Laser Damage Helps the Eavesdropper in Quantum Cryptography

• We propose a class of attacks on quantum key distribution (QKD) systems where an eavesdropper actively engineers new loopholes by using damaging laser illumination to permanently change properties of system components. This can turn a perfect QKD system into a completely insecure system. A proof-of-principle experiment performed on an avalanche photodiode-based detector shows that laser damage can be used to create loopholes. After similar to 1 W illumination, the detectors' dark count rate reduces 2-5 times, permanently improving single-photon counting performance. After similar to 1.5 W, the detectors switch permanently into the linear photodetection mode and become completely insecure for QKD applications.

Subject headings

NATURVETENSKAP  -- Fysik -- Annan fysik (hsv//swe)

NATURAL SCIENCES  -- Physical Sciences -- Other Physics Topics (hsv//eng)

Keyword

Tailored Bright Illumination

Key Distribution

Avalanche Photodiodes

Security

Mechanisms

Photons

Devices

Attack

Publication and Content Type

ref (subject category)

art (subject category)