# Trojan-horse attacks threaten the security of practical quantum cryptography

@article{Jain2014TrojanhorseAT, title={Trojan-horse attacks threaten the security of practical quantum cryptography}, author={Nitin Jain and Elena Anisimova and Imran Khan and Vadim Makarov and Christoph Marquardt and Gerd Leuchs}, journal={New Journal of Physics}, year={2014}, volume={16}, pages={123030} }

A quantum key distribution (QKD) system may be probed by an eavesdropper Eve by sending in bright light from the quantum channel and analyzing the back-reflections. We propose and experimentally demonstrate a setup for mounting such a Trojan-horse attack. We show it in operation against the quantum cryptosystem Clavis2 from ID Quantique, as a proof-of-principle. With just a few back-reflected photons, Eve discerns Bobʼs (secret) basis choice, and thus the raw key bit in the Scarani–Acin–Ribordy… Expand

#### 93 Citations

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- Computer Science
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This paper analyzed the Trojan horse attacks with different wavelengths and confirmed its side effects, such as crosstalk and anti-Stokes Raman scattering, by a numerical simulation and presented a practical way to estimate the deviation of shot noise and correct the excess noise by inserting different wavelength pulses under joint attacks. Expand

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This thesis presents three experimental studies of attacks on quantum key distribution (QKD) systems, including a demonstration of Eve’s ability to force a commercial system to distill a key from a raw key of a short length, where the asymptotic assumption of security claimed by the manufacturer might not hold. Expand

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Security analyses of quantum cryptographic protocols typically rely on certain conditions; one such condition is that the sender (Alice) and receiver (Bob) have isolated devices inaccessible to third… Expand

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- Physics, Mathematics
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In this article we present a new prepare and measure quantum key distribution protocol that decouples the necessary quantum channel error estimation from its dependency on sifting, or otherwise… Expand

Risk Analysis of Trojan-Horse Attacks on Practical Quantum Key Distribution Systems

- Physics
- IEEE Journal of Selected Topics in Quantum Electronics
- 2015

An eavesdropper Eve may probe a quantum key distribution (QKD) system by sending a bright pulse from the quantum channel into the system and analyzing the back-reflected pulses. Such Trojan-horse… Expand

Practical security bounds against the Trojan-horse attack in quantum key distribution

- Computer Science, Physics
- 2015

The Trojan-horse attack is turned into an information leakage problem and the system security is quantified and related to the specification of the optical elements most relevant to security. Expand

Invisible Trojan-horse attack

- Computer Science, Physics
- Scientific Reports
- 2017

It is demonstrated experimentally that the noise response of the detectors to bright pulses is greatly reduced, and by modeling that the same attack will succeed, the invisible nature of the attack poses a threat to the security of practical QKD if proper countermeasures are not adopted. Expand

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- Computer Science, Medicine
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- 2017

A QKD system designed with this goal in mind is reported, providing a more resilient target against possible hacking attacks including Trojan horse, detector blinding, phase randomisation and photon number splitting attacks. Expand

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- Computer Science, Medicine
- Scientific Reports
- 2018

This paper reveals the security risk of the calibration process of a passive-basis-choice BB84 QKD system by launching a quantum man-in-the-middle attack which intercepts all calibration signals and resends faked ones, and proposes a basis-dependent detector efficiency mismatch (BEM) based faked states attack on a single photon BB84QKD to stress the threat of BEM. Expand

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- Computer Science
- 2018

This thesis further investigates the practical security of quantum cryptography in and beyond MDI quantum cryptography, and shows that detector-device-independent (DDI) QKD security is not equivalent to that of MDIQKD and, further, that DDI QKKD is insecure against detector side-channel attacks. Expand

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