Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

arXiv:quant-ph/0304075 · Physical Review Letters

Decoherence-Free Subspaces in Quantum Key Distribution

Zachary Walton, Ayman F. Abouraddy, Alexander V. Sergienko, Bahaa E. A. Saleh, Malvin Carl Teich

Published Aug 20, 2003• 202 citations
arXivHTMLPDF

Abstract

We demonstrate that two recent innovations in the field of practical quantum key distribution (one-way autocompensation and passive detection) are closely related to the methods developed to protect quantum computations from decoherence. We present a new scheme that combines these advantages, and propose a practical implementation of this scheme that is feasible using existing technology.

DOI
10.1103/physrevlett.91.087901

Related papers

Decoherence-free subspaces in quantum key distribution

Zachary Walton, Ayman F. Abouraddy, Alexander V. Sergienko +2 more

We demonstrate that two recent innovations in the field of practical quantum key distribution (noise-immunity and passive detection) are closely related to the methods developed to protect quantum computations from decoherence. We present a new scheme that combines these advantages, and propose a practical implementation of this scheme that is feasible using existing technology.

Frontiers in Optics•Jan 1, 2003•12 citations

Passive autocompensating quantum cryptography

Zachary Walton, Ayman F. Abouraddy, Alexander V. Sergienko +2 more

A new quantum cryptography scheme is presented that combines passive detection and autocompensation, two desirable features that have hitherto only been demonstrated in separate implementations. A practical implementation based on a well-known down-conversion source is proposed.

European Quantum Electronics Conference (EQEC)•Nov 15, 2004•0 citations

Decoy states for quantum key distribution based on decoherence-free subspaces

Zhen−Qiang Yin, Yibo Zhao, Zheng-Wei Zhou +2 more

A quantum key distribution with decoherence-free subspaces has been proposed to overcome collective noise to the polarization modes of photons flying in quantum channels. Prototypes of this scheme have also been achieved with a parametric down-conversion source. However, the photon-number-splitting attack we propose will make practical implementations of this scheme insecure since the parametric down-conversion source may occasionally emit multiphoton pairs. We propose a decoy-state method to make these implementations immune to this attack. With this decoy-state method, both the security distance and key bit rate will be increased.

arXiv:0803.1594•Physical Review A•Jun 17, 2008•21 citations

Time bin quantum key distribution protocols for free space communications

Alfonso Tello Castillo, Elizabeth Eso, Ross J. Donaldson

Quantum key distribution (QKD) is a promising technology to enable secure cryptography after quantum computers have been developed. It allows for a key growing protocol that permits creating absolutely random keys to be used in the onetime pad codification scheme. Enabling a global QKD network is one of the final goals of the field. However, to do this with conventional optical fibres presents a fundamental limitation due to their intrinsic loss. Free-space, and specifically satellite links, have been proposed as an alternative and have gathered a lot of interest in recent years. They are considered one of the best candidates to enable a global network. Free-space QKD implementations are dominated by polarisation encoding protocols due to the relative transparency of the atmosphere to polarization. Nonetheless, time-bin and phase codifications offer some advantages and can be practical thanks to new passive interferometer designs. In this paper, the first free-space Coherent One-Way (COW) implementation is reported, some design considerations are commented, and the results of the experiment are shown. These show how time-bin/phase codifications are interesting candidates for free-space QKD.

Quantum Communications and Quantum Imaging•Oct 4, 2022•0 citations

Phase-Matching Quantum Key Distribution

Xiongfeng Ma, Pei Zeng, Hongyi Zhou

A method for distributing encryption keys in a quantum network surpasses current limits and is immune to all detection attacks, potentially offering a new standard for future implementations of quantum key distribution.

arXiv:1805.05538•Physical Review X•Aug 16, 2018•324 citations

Symmetric Autocompensating Quantum Key Distribution

Zachary Walton, Alexander V. Sergienko, Lev B. Levitin +2 more

We present quantum key distribution schemes which are autocompensating (require no alignment) and symmetric (Alice and Bob receive photons from a central source) for both polarization and time-bin qubits. The primary benefit of the symmetric configuration is that both Alice and Bob may have passive setups (neither Alice nor Bob is required to make active changes for each run of the protocol). We show that both the polarization and the time-bin schemes may be implemented with existing technology. The new schemes are related to previously described schemes by the concept of advanced waves.

•Sep 4, 2003•1 citation
We demonstrate that two recent innovations in the field of practical quantum key distribution (one-way autocompensation and passive detection) are closely related to the methods developed to protect quantum computations from decoherence. We present a new scheme that combines these advantages, and propose a practical implementation of this scheme that is feasible using existing technology.
A quantum key distribution with decoherence-free subspaces has been proposed to overcome collective noise to the polarization modes of photons flying in quantum channels. Prototypes of this scheme have also been achieved with a parametric down-conversion source. However, the photon-number-splitting attack we propose will make practical implementations of this scheme insecure since the parametric down-conversion source may occasionally emit multiphoton pairs. We propose a decoy-state method to make these implementations immune to this attack. With this decoy-state method, both the security distance and key bit rate will be increased.
Quantum key distribution (QKD) is a promising technology to enable secure cryptography after quantum computers have been developed. It allows for a key growing protocol that permits creating absolutely random keys to be used in the onetime pad codification scheme. Enabling a global QKD network is one of the final goals of the field. However, to do this with conventional optical fibres presents a fundamental limitation due to their intrinsic loss. Free-space, and specifically satellite links, have been proposed as an alternative and have gathered a lot of interest in recent years. They are considered one of the best candidates to enable a global network. Free-space QKD implementations are dominated by polarisation encoding protocols due to the relative transparency of the atmosphere to polarization. Nonetheless, time-bin and phase codifications offer some advantages and can be practical thanks to new passive interferometer designs. In this paper, the first free-space Coherent One-Way (COW) implementation is reported, some design considerations are commented, and the results of the experiment are shown. These show how time-bin/phase codifications are interesting candidates for free-space QKD.
We present quantum key distribution schemes which are autocompensating (require no alignment) and symmetric (Alice and Bob receive photons from a central source) for both polarization and time-bin qubits. The primary benefit of the symmetric configuration is that both Alice and Bob may have passive setups (neither Alice nor Bob is required to make active changes for each run of the protocol). We show that both the polarization and the time-bin schemes may be implemented with existing technology. The new schemes are related to previously described schemes by the concept of advanced waves.