scholarly journals Quantum key distribution with delayed privacy amplification and its application to the security proof of a two-way deterministic protocol

2012 ◽  
Vol 85 (3) ◽  
Author(s):  
Chi-Hang Fred Fung ◽  
Xiongfeng Ma ◽  
H. F. Chau ◽  
Qing-yu Cai
Keyword(s):  
Quantum Key Distribution ◽  
Key Distribution ◽  
Privacy Amplification ◽  
Security Proof

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.

Everlasting security of quantum key distribution with 1K-DWCDM and quadratic hash

2021 ◽  
Vol 21 (3&4) ◽  
pp. 0181-0202
Author(s):  
Khodakhast Bibak ◽  
Robert Ritchie ◽  
Behrouz Zolfaghari
Keyword(s):  
Hash Function ◽  
Quantum Key Distribution ◽  
Key Distribution ◽  
Privacy Amplification ◽  
Universal Hashing ◽  
Wide Range ◽  
Strong Property ◽  
Everlasting Security ◽  
Universal Hash Function ◽  
General Method

Quantum key distribution (QKD) offers a very strong property called everlasting security, which says if authentication is unbroken during the execution of QKD, the generated key remains information-theoretically secure indefinitely. For this purpose, we propose the use of certain universal hashing based MACs for use in QKD, which are fast, very efficient with key material, and are shown to be highly secure. Universal hash functions are ubiquitous in computer science with many applications ranging from quantum key distribution and information security to data structures and parallel computing. In QKD, they are used at least for authentication, error correction, and privacy amplification. Using results from Cohen [Duke Math. J., 1954], we also construct some new families of $\varepsilon$-almost-$\Delta$-universal hash function families which have much better collision bounds than the well-known Polynomial Hash. Then we propose a general method for converting any such family to an $\varepsilon$-almost-strongly universal hash function family, which makes them useful in a wide range of applications, including authentication in QKD.

Scheme Design of Highly Efficient Privacy Amplification with Fewer Random Seeds in Quantum Key Distribution

2017 ◽  
Vol 37 (2) ◽  
pp. 0227002
Author(s):  
刘翼鹏 Liu Yipeng ◽  
郭建胜 Guo Jiansheng ◽  
崔竞一 Cui Jingyi
Keyword(s):  
Quantum Key Distribution ◽  
Key Distribution ◽  
Privacy Amplification ◽  
Scheme Design ◽  
Highly Efficient

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.

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