Hacking single-photon avalanche detectors in quantum key distribution via pulse illumination

Area of Science:

• Quantum Information Science
• Cybersecurity
• Experimental Physics

Background:

• Quantum key distribution (QKD) offers theoretical information-theoretic security.
• Practical implementations suffer from device imperfections, creating security vulnerabilities.
• Existing security patches aim to mitigate known loopholes in QKD systems.

Purpose of the Study:

• To investigate the security of practical QKD systems against novel attacks.
• To demonstrate the vulnerability of existing security patches to exploitation.
• To introduce and analyze a new attack vector: the pulse illumination attack.

Main Methods:

• Experimental demonstration of the pulse illumination attack on a QKD detector.
• Analysis of the photocurrent monitor patch's vulnerability.
• Theoretical analysis of the secret key rate under the pulse illumination attack.

Main Results:

• The pulse illumination attack successfully bypasses the photocurrent monitor patch, a common defense against detector blinding attacks.
• Experimental evidence confirms the attack's efficacy in compromising the QKD system's security.
• Theoretical analysis validates that an eavesdropper (Eve) can extract secret key information.

Conclusions:

• Device imperfections in practical QKD systems remain a significant security concern.
• Security patches themselves can introduce new vulnerabilities exploitable by sophisticated attacks.
• The pulse illumination attack highlights the need for rigorous security evaluation of QKD detection units and suggests its inclusion in QKD security standards.