scholarly journals Security of quantum key distribution with bit and basis dependent detector flaws

2010 ◽  
Vol 10 (1&2) ◽  
pp. 60-76
Author(s):  
L. Lydersen ◽  
J. Skaar
Keyword(s):  
Quantum Key Distribution ◽  
Key Distribution ◽  
Detector Efficiency ◽  
Bb84 Protocol ◽  
Security Proof ◽  
Linear Optical ◽  
Detector Model

We consider the security of the Bennett-Brassard 1984 (BB84) protocol for Quantum Key Distribution (QKD), in the presence of bit and basis dependent detector flaws. We suggest a powerful attack that can be used in systems with detector efficiency mismatch, even if the detector assignments are chosen randomly by Bob. A security proof is provided, valid for any basis dependent, possibly lossy, linear optical imperfections in the channel/receiver/detectors. The proof does not assume the so-called squashing detector model.

The security analysis of the BB84 protocol in the case of Calderbank–Shor–Steane code leakage

2022 ◽  
Author(s):  
Ming Fang ◽  
Ya-Ping Li ◽  
Li Fei
Keyword(s):  
Distribution System ◽  
Quantum Key Distribution ◽  
Quantum Physics ◽  
Security Analysis ◽  
Key Distribution ◽  
Entanglement Purification ◽  
Bb84 Protocol ◽  
Security Proof ◽  
The Impact ◽  
The Relationship

Quantum key distribution (QKD) allows authenticated parties to share secure keys. Its security comes from quantum physics rather than computational complexity. The previous work has been able to demonstrate the security of the BB84 protocol based on the uncertainty principle, entanglement purification and information theory. In the security proof method based on entanglement purification, it is assumed that the information of Calderbank–Shor–Steane (CSS) error correction code cannot be leaked, otherwise, it is insecure. However, there is no quantitative analysis of the relationship between the parameter of CSS code and the amount of information leaked. In the attack and defense strategy of the actual quantum key distribution system, especially in the application of the device that is easy to lose or out of control, it is necessary to assess the impact of the parameter leakage. In this paper, we derive the relationship between the leaked parameter of CSS code and the amount of the final key leakage based on the BB84 protocol. Based on this formula, we simulated the impact of different CSS code parameter leaks on the final key amount. Through the analysis of simulation results, the security of the BB84 protocol is inversely proportional to the value of [Formula: see text] and [Formula: see text] in the case of the CSS code leak.

scholarly journals CONTINUOUS-VARIABLE QUANTUM KEY DISTRIBUTION PROTOCOLS WITH EIGHT-STATE DISCRETE MODULATION

2012 ◽  
Vol 10 (01) ◽  
pp. 1250004 ◽  
Author(s):  
A. BECIR ◽  
F. A. A. EL-ORANY ◽  
M. R. B. WAHIDDIN
Keyword(s):  
Quantum Key Distribution ◽  
Coherent States ◽  
Key Distribution ◽  
Continuous Variable ◽  
Excess Noise ◽  
Electronic Noise ◽  
Detector Efficiency ◽  
Security Proof ◽  
Quantum Key Distribution Protocol ◽  
Noisy Quantum Channel

We propose a continuous variable quantum key distribution protocol based on discrete modulation of eight-state coherent states. We present a rigorous security proof against the collective attacks by taking into consideration the realistic lossy and noisy quantum channel, the imperfect detector efficiency, and the detector electronic noise. This protocol shows high tolerance against excess noise and promises to achieve over 100 km distance of optical fiber.

scholarly journals Apply current exponential de Finetti theorem to realistic quantum key distribution

2014 ◽  
Vol 33 ◽  
pp. 1460370 ◽  
Author(s):  
Yi-Bo Zhao ◽  
Zhen-Qiang Yin
Keyword(s):  
Quantum Key Distribution ◽  
Key Distribution ◽  
Small Error ◽  
Heterodyne Detection ◽  
Finite Dimensional Subspace ◽  
Dimensional System ◽  
Finite Dimensional ◽  
Security Proof ◽  
De Finetti Theorem ◽  
De Finetti

In the realistic quantum key distribution (QKD), Alice and Bob respectively get a quantum state from an unknown channel, whose dimension may be unknown. However, while discussing the security, sometime we need to know exact dimension, since current exponential de Finetti theorem, crucial to the information-theoretical security proof, is deeply related with the dimension and can only be applied to finite dimensional case. Here we address this problem in detail. We show that if POVM elements corresponding to Alice and Bob's measured results can be well described in a finite dimensional subspace with sufficiently small error, then dimensions of Alice and Bob's states can be almost regarded as finite. Since the security is well defined by the smooth entropy, which is continuous with the density matrix, the small error of state actually means small change of security. Then the security of unknown-dimensional system can be solved. Finally we prove that for heterodyne detection continuous variable QKD and differential phase shift QKD, the collective attack is optimal under the infinite key size case.

scholarly journals DECOY STATE QUANTUM KEY DISTRIBUTION

2005 ◽  
Vol 03 (supp01) ◽  
pp. 143-143 ◽  
Author(s):  
HOI-KWONG LO
Keyword(s):  
Quantum Key Distribution ◽  
Secure Communication ◽  
Key Distribution ◽  
Generation Rate ◽  
Key Generation ◽  
Long Distance ◽  
Decoy State ◽  
Bb84 Protocol ◽  
High Loss ◽  
Statistical Fluctuations

Quantum key distribution (QKD) allows two parties to communicate in absolute security based on the fundamental laws of physics. Up till now, it is widely believed that unconditionally secure QKD based on standard Bennett-Brassard (BB84) protocol is limited in both key generation rate and distance because of imperfect devices. Here, we solve these two problems directly by presenting new protocols that are feasible with only current technology. Surprisingly, our new protocols can make fiber-based QKD unconditionally secure at distances over 100km (for some experiments, such as GYS) and increase the key generation rate from O(η2) in prior art to O(η) where η is the overall transmittance. Our method is to develop the decoy state idea (first proposed by W.-Y. Hwang in "Quantum Key Distribution with High Loss: Toward Global Secure Communication", Phys. Rev. Lett. 91, 057901 (2003)) and consider simple extensions of the BB84 protocol. This part of work is published in "Decoy State Quantum Key Distribution", . We present a general theory of the decoy state protocol and propose a decoy method based on only one signal state and two decoy states. We perform optimization on the choice of intensities of the signal state and the two decoy states. Our result shows that a decoy state protocol with only two types of decoy states—a vacuum and a weak decoy state—asymptotically approaches the theoretical limit of the most general type of decoy state protocols (with an infinite number of decoy states). We also present a one-decoy-state protocol as a special case of Vacuum+Weak decoy method. Moreover, we provide estimations on the effects of statistical fluctuations and suggest that, even for long distance (larger than 100km) QKD, our two-decoy-state protocol can be implemented with only a few hours of experimental data. In conclusion, decoy state quantum key distribution is highly practical. This part of work is published in "Practical Decoy State for Quantum Key Distribution", . We also have done the first experimental demonstration of decoy state quantum key distribution, over 15km of Telecom fibers. This part of work is published in "Experimental Decoy State Quantum Key Distribution Over 15km", .

scholarly journals Finite-key analysis for twin-field quantum key distribution with composable security

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Hua-Lei Yin ◽  
Zeng-Bing Chen
Keyword(s):  
Coherent State ◽  
Quantum Key Distribution ◽  
Key Distribution ◽  
Practical Implementation ◽  
Fluctuation Analysis ◽  
Statistical Fluctuation ◽  
Secret Key ◽  
Quantum Repeater ◽  
Long Distance ◽  
Security Proof

AbstractLong-distance quantum key distribution (QKD) has long time seriously relied on trusted relay or quantum repeater, which either has security threat or is far from practical implementation. Recently, a solution called twin-field (TF) QKD and its variants have been proposed to overcome this challenge. However, most security proofs are complicated, a majority of which could only ensure security against collective attacks. Until now, the full and simple security proof can only be provided with asymptotic resource assumption. Here, we provide a composable finite-key analysis for coherent-state-based TF-QKD with rigorous security proof against general attacks. Furthermore, we develop the optimal statistical fluctuation analysis method to significantly improve secret key rate in high-loss regime. The results show that coherent-state-based TF-QKD is practical and feasible, with the potential to apply over nearly one thousand kilometers.

scholarly journals Secure polarization-independent subcarrier quantum key distribution in optical fiber channel using BB84 protocol with a strong reference

2016 ◽  
Vol 24 (3) ◽  
pp. 2619 ◽  
Author(s):  
A. V. Gleim ◽  
V. I. Egorov ◽  
Yu. V. Nazarov ◽  
S. V. Smirnov ◽  
V. V. Chistyakov ◽  
...  
Keyword(s):  
Optical Fiber ◽  
Quantum Key Distribution ◽  
Key Distribution ◽  
Bb84 Protocol ◽  
Fiber Channel ◽  
Polarization Independent

Practical decoy state quantum key distribution with detector efficiency mismatch

2018 ◽  
Vol 72 (6) ◽  
Author(s):  
Yang-yang Fei ◽  
Xiang-dong Meng ◽  
Ming Gao ◽  
Zhi Ma ◽  
Hong Wang
Keyword(s):  
Quantum Key Distribution ◽  
Key Distribution ◽  
Detector Efficiency ◽  
Decoy State
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