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", .

The enhanced measurement-device-independent quantum key distribution with heralded pair coherent state

2019 ◽  
Vol 34 (04) ◽  
pp. 2050063
Author(s):  
Yefeng He ◽  
Wenping Ma
Keyword(s):  
Light Source ◽  
Error Rate ◽  
Quantum Key Distribution ◽  
Key Distribution ◽  
Generation Rate ◽  
Key Generation ◽  
Measurement Device ◽  
Decoy State ◽  
Communication Distance ◽  
Measurement Device Independent

With heralded pair coherent states (HPCS), orbital angular momentum (OAM) states and pulse position modulation (PPM) technology, a decoy-state measurement-device-independent quantum key distribution (MDI-QKD) protocol is proposed. OAM states and PPM technology are used to realize the coding of the signal states in the HPCS light source. The use of HPCS light source, OAM coding and PPM coding cannot only reduce the error rate but also improve the key generation rate and communication distance. The new MDI-QKD protocol also employs three-intensity decoy states to avoid the attacks against the light source. By calculating the error rate and key generation rate, the performance of the MDI-QKD protocol is analyzed. Numerical simulation shows that the protocol has very low error rate and very high key generation rate. Moreover, the maximum communication distance can reach 455 km.

scholarly journals Decoy-State Quantum Key Distribution Over a Long-Distance High-Loss Air-Water Channel

2021 ◽  
Vol 15 (2) ◽  
Author(s):  
Cheng-Qiu Hu ◽  
Zeng-Quan Yan ◽  
Jun Gao ◽  
Zhan-Ming Li ◽  
Heng Zhou ◽  
...  
Keyword(s):  
Quantum Key Distribution ◽  
Water Channel ◽  
Key Distribution ◽  
Long Distance ◽  
Decoy State ◽  
High Loss

scholarly journals DECOY STATE QUANTUM KEY DISTRIBUTION

2010 ◽  
Vol 10 (2) ◽  
pp. 81-86
Author(s):  
Sellami Ali
Keyword(s):  
Distribution System ◽  
Quantum Key Distribution ◽  
Fiber Length ◽  
Key Distribution ◽  
Generation Rate ◽  
Key Generation ◽  
Decoy State ◽  
Set Up

Experimental weak + vacuum protocol has been demonstrated using commercial QKD system based on a standard bi-directional ‘Plug & Play’ set-up. By making simple modifications to a commercial quantum key distribution system, decoy state QKD allows us to achieve much better performance than QKD system without decoy state in terms of key generation rate and distance. We demonstrate an unconditionally secure key rate of 6.2931 x 10-4per pulse for a 25 km fiber length.

scholarly journals Security of high speed quantum key distribution with finite detector dead time

2014 ◽  
Vol 14 (3&4) ◽  
pp. 217-235
Author(s):  
Viacheslav Burenkov ◽  
Bing Qi ◽  
Ben Fortescue ◽  
Hoi-Kwong Lo
Keyword(s):  
Distribution System ◽  
Quantum Key Distribution ◽  
High Speed ◽  
Dead Time ◽  
Detection Efficiency ◽  
Transmission Rate ◽  
Key Distribution ◽  
Generation Rate ◽  
Key Generation ◽  
Bb84 Protocol

The security of a high speed quantum key distribution system with finite detector dead time $\tau$ is analyzed. When the transmission rate becomes higher than the maximum count rate of the individual detectors ($1/\tau$), security issues affect the scheme for sifting bits. Analytical calculations and numerical simulations of the Bennett-Brassard BB84 protocol are performed. We study Rogers et al.'s scheme (further information is available in [D. J. Rogers, J. C. Bienfang, A. Nakassis, H. Xu, and C. W. Clark, New J. Phys.~{\bf 9}, 319 (2007)]) in the presence of an active eavesdropper Eve who has the power to perform an intercept-resend attack. It is shown that Rogers et al.'s scheme is no longer guaranteed to be secure. More specifically, Eve can induce a basis-dependent detection efficiency at the receiver's end. Modified key sifting schemes that are basis-independent and thus secure in the presence of dead time and an active eavesdropper are then introduced. We analyze and compare these secure sifting schemes for this active Eve scenario, and calculate and simulate their key generation rate. It is shown that the maximum key generation rate is $1/(2\tau)$ for passive basis selection, and $1/\tau$ for active basis selection. The security analysis for finite detector dead time is also extended to the decoy state BB84 protocol for one particular secure sifting scheme.

scholarly journals Experimental Long-Distance Decoy-State Quantum Key Distribution Based on Polarization Encoding

2007 ◽  
Vol 98 (1) ◽  
Author(s):  
Cheng-Zhi Peng ◽  
Jun Zhang ◽  
Dong Yang ◽  
Wei-Bo Gao ◽  
Huai-Xin Ma ◽  
...  
Keyword(s):  
Quantum Key Distribution ◽  
Key Distribution ◽  
Long Distance ◽  
Decoy State ◽  
Polarization Encoding

Security proof of quantum key distribution with detection efficiency mismatch

2009 ◽  
Vol 9 (1&2) ◽  
pp. 131-165
Author(s):  
C.-H. F. Fung ◽  
K. Tamaki ◽  
B. Qi ◽  
H.-K. Lo ◽  
X. Ma
Keyword(s):  
Quantum Key Distribution ◽  
Detection Efficiency ◽  
Key Distribution ◽  
Unconditional Security ◽  
Generation Rate ◽  
Key Generation ◽  
Efficiency Ratio ◽  
Physical Origin ◽  
Security Proof ◽  
Time Domains

In theory, quantum key distribution (QKD) offers unconditional security based on the laws of physics. However, as demonstrated in recent quantum hacking theory and experimental papers, detection efficiency loophole can be fatal to the security of practical QKD systems. Here, we describe the physical origin of detection efficiency mismatch in various domains including spatial, spectral, and time domains and in various experimental set-ups. More importantly, we prove the unconditional security of QKD even with detection efficiency mismatch. We explicitly show how the key generation rate is characterized by the maximal detection efficiency ratio between the two detectors. Furthermore, we prove that by randomly switching the bit assignments of the detectors, the effect of detection efficiency mismatch can be completely eliminated.

scholarly journals Decoy-state quantum key distribution with both source errors and statistical fluctuations

2009 ◽  
Vol 11 (7) ◽  
pp. 075006 ◽  
Author(s):  
Xiang-Bin Wang ◽  
Lin Yang ◽  
Cheng-Zhi Peng ◽  
Jian-Wei Pan
Keyword(s):  
Quantum Key Distribution ◽  
Key Distribution ◽  
Decoy State ◽  
Statistical Fluctuations ◽  
Source Errors

scholarly journals Quantum Key Distribution Based-on Refraction and Polarization Entanglement

2020 ◽  
Vol 8 (6) ◽  
pp. 2911-2918
Keyword(s):  
Quantum Key Distribution ◽  
Secure Communication ◽  
Key Distribution ◽  
Public Key ◽  
Entangled State ◽  
Key Generation ◽  
Secret Key ◽  
The Public ◽  
Encryption And Decryption ◽  
Refraction Factor

Cryptography is the specialty of encoding and decoding messages and exists as extended as the individuals have doubted from one another and need secure correspondence. The traditional techniques for encryption naturally depend on any among public key or secret key approaches. In general, the public key encryption depends on two keys, for example, public key and private key. Since encryption and decryption keys are different, it isn't important to safely distribute a key. In this approach, the difficult of the numerical issues is assumed, not demonstrated. All the security will be easily compromised if proficient factoring algorithms are found. In secret key encryption two clients at first create secret key, which is a long string of arbitrarily selected bits and safely shares between them. At that point the clients can utilize the secret key along with the algorithms to encryption and decryption information. The procedures are complicated and also planned such a way that every bit of output is based on every bit of input. There are two fundamental issues with secret key encryption; first one is that by breaking down the openly known encoding algorithms, it gets simpler to decrypt the message. The subsequent one is that it experiences key-conveyance issue. As a result of the ongoing improvements in quantum processing and quantum data hypothesis, the quantum computers presents genuine difficulties to generally utilized current cryptographic strategy. The improvement of quantum cryptography beat the deficiencies of old style cryptography and achieves these huge accomplishments by using the properties of infinitesimal articles, for example, photon with its polarization and entangled state. In this paper, Polarization by refraction based quantum key distribution (PR-QKD) is proposed for quantum key generation and distribution. The proposed work considers three basis of polarization such as rectilinear (horizontal and vertical), circular (left-circular and right-circular), ellipse (left-ellipse and rightellipse) and refraction factor. This quantum key can be used for secure communication between two users who are spatially separated and also offer intrusion detection ability to detect attackers. The theoretical approach and conceptual results are discussed in this paper.

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