dorsal/arxiv
View SchemaPhase-Remapping Attack in Practical Quantum Key Distribution Systems
| Authors | Chi-Hang Fred Fung, Bing Qi, Kiyoshi Tamaki, Hoi-Kwong Lo |
|---|---|
| Categories | |
| ArXiv ID | quant-ph/0601115 |
| URL | https://arxiv.org/abs/quant-ph/0601115 |
| DOI | 10.1103/PhysRevA.75.032314 |
| Journal | Phys. Rev. A 75, 032314 (2007) |
Abstract
Quantum key distribution (QKD) can be used to generate secret keys between two distant parties. Even though QKD has been proven unconditionally secure against eavesdroppers with unlimited computation power, practical implementations of QKD may contain loopholes that may lead to the generated secret keys being compromised. In this paper, we propose a phase-remapping attack targeting two practical bidirectional QKD systems (the "plug & play" system and the Sagnac system). We showed that if the users of the systems are unaware of our attack, the final key shared between them can be compromised in some situations. Specifically, we showed that, in the case of the Bennett-Brassard 1984 (BB84) protocol with ideal single-photon sources, when the quantum bit error rate (QBER) is between 14.6% and 20%, our attack renders the final key insecure, whereas the same range of QBER values has been proved secure if the two users are unaware of our attack; also, we demonstrated three situations with realistic devices where positive key rates are obtained without the consideration of Trojan horse attacks but in fact no key can be distilled. We remark that our attack is feasible with only current technology. Therefore, it is very important to be aware of our attack in order to ensure absolute security. In finding our attack, we minimize the QBER over individual measurements described by a general POVM, which has some similarity with the standard quantum state discrimination problem.
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"abstract": "Quantum key distribution (QKD) can be used to generate secret keys between\ntwo distant parties. Even though QKD has been proven unconditionally secure\nagainst eavesdroppers with unlimited computation power, practical\nimplementations of QKD may contain loopholes that may lead to the generated\nsecret keys being compromised. In this paper, we propose a phase-remapping\nattack targeting two practical bidirectional QKD systems (the \"plug \u0026 play\"\nsystem and the Sagnac system). We showed that if the users of the systems are\nunaware of our attack, the final key shared between them can be compromised in\nsome situations. Specifically, we showed that, in the case of the\nBennett-Brassard 1984 (BB84) protocol with ideal single-photon sources, when\nthe quantum bit error rate (QBER) is between 14.6% and 20%, our attack renders\nthe final key insecure, whereas the same range of QBER values has been proved\nsecure if the two users are unaware of our attack; also, we demonstrated three\nsituations with realistic devices where positive key rates are obtained without\nthe consideration of Trojan horse attacks but in fact no key can be distilled.\nWe remark that our attack is feasible with only current technology. Therefore,\nit is very important to be aware of our attack in order to ensure absolute\nsecurity. In finding our attack, we minimize the QBER over individual\nmeasurements described by a general POVM, which has some similarity with the\nstandard quantum state discrimination problem.",
"arxiv_id": "quant-ph/0601115",
"authors": [
"Chi-Hang Fred Fung",
"Bing Qi",
"Kiyoshi Tamaki",
"Hoi-Kwong Lo"
],
"categories": [
"quant-ph",
"cs.IT",
"math.IT"
],
"doi": "10.1103/PhysRevA.75.032314",
"journal_ref": "Phys. Rev. A 75, 032314 (2007)",
"title": "Phase-Remapping Attack in Practical Quantum Key Distribution Systems",
"url": "https://arxiv.org/abs/quant-ph/0601115"
},
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