Editing Quantum key distribution (section)

=== Quantum key distribution networks ===

==== DARPA ====
The [[DARPA Quantum Network]],<ref>{{cite web|url=https://www.newscientist.com/article/dn7484|title=Quantum cryptography network gets wireless link|first=Will|last=Knight|access-date=18 August 2016}}</ref> was a 10-node quantum key distribution network, which ran continuously for four years, 24 hours a day, from 2004 to 2007 in Massachusetts in the United States. It was developed by [[BBN Technologies]], [[Harvard University]], [[Boston University]], with collaboration from [[IBM Research]], the [[National Institute of Standards and Technology]], and [[QinetiQ]]. It supported a standards-based Internet [[computer network]] protected by quantum key distribution.

==== SECOQC ====
{{main|Secure Communication based on Quantum Cryptography}}
The world's first [[computer network]] protected by quantum key distribution was implemented in October 2008, at a scientific conference in Vienna. The name of this network is [[Secure Communication based on Quantum Cryptography|SECOQC]] ('''Se'''cure '''Co'''mmunication Based on '''Q'''uantum '''C'''ryptography) and the [[European Union|EU]] funded this project. The network used 200&nbsp;km of standard [[fibre-optic cable]] to interconnect six locations across Vienna and the town of [[St Poelten]] located 69&nbsp;km to the west.<ref>{{cite news|url=http://news.bbc.co.uk/1/hi/sci/tech/7661311.stm|title='Unbreakable' encryption unveiled|date=9 October 2008|access-date=18 August 2016|via=bbc.co.uk}}</ref>

==== SwissQuantum ====
Id Quantique has successfully completed the longest running project for testing Quantum Key Distribution (QKD) in a field environment. The main goal of the SwissQuantum network project installed in the Geneva metropolitan area in March 2009, was to validate the reliability and robustness of QKD in continuous operation over a long time period in a field environment. The quantum layer operated for nearly 2 years until the project was shut down in January 2011 shortly after the initially planned duration of the test.

==== Chinese networks ====
In May 2009, a hierarchical quantum network was demonstrated in [[Wuhu]], [[China]]. The hierarchical network consisted of a backbone network of four nodes connecting a number of subnets. The backbone nodes were connected through an optical switching quantum router. Nodes within each subnet were also connected through an optical switch, which were connected to the backbone network through a trusted relay.<ref>{{citation
| title=Field experiment on a robust hierarchical metropolitan quantum cryptography network
| first1=FangXing  | last1=Xu
| first2=Wei       | last2=Chen
| first3=Shuang    | last3=Wang
| first4=ZhenQiang | last4=Yin
| first5=Yang      | last5=Zhang
| first6=Yun       | last6=Liu
| first7=Zheng     | last7=Zhou
| first8=YiBo      | last8=Zhao
| first9=HongWei   | last9=Li
| first10=Dong     | last10=Liu
| journal=Chinese Science Bulletin
| volume=54
| issue=17
| pages=2991–2997
| date=2009
| doi=10.1007/s11434-009-0526-3
| bibcode=2009ChSBu..54.2991X  | arxiv=0906.3576| s2cid=118300112 }}</ref>

Launched in August 2016, the [[Quantum Experiments at Space Scale|QUESS]] space mission created an international QKD channel between China and the [[Institute for Quantum Optics and Quantum Information]] in [[Vienna]], [[Austria]] − a ground distance of {{convert|7500|km|mi|abbr=on}}, enabling the first intercontinental secure quantum video call.<ref name="IOP">{{cite news|url=http://physicsworld.com/cws/article/news/2016/aug/16/china-launches-world-s-first-quantum-science-satellite|title=China launches world's first quantum science satellite|author=Lin Xing|newspaper=Physics World|publisher=Institute of Physics|date=16 August 2016|access-date=17 August 2016|archive-date=1 December 2017|archive-url=https://web.archive.org/web/20171201030546/http://physicsworld.com/cws/article/news/2016/aug/16/china-launches-world-s-first-quantum-science-satellite|url-status=dead}}</ref><ref name="OeAW">{{cite web |url = http://www.oeaw.ac.at/en/events-communication/public-relations-communication/public-relations-communication/ausgewaehlte-oeaw-pressemeldungen/press-releases/first-quantum-satellite-successfully-launched/ |title = First Quantum Satellite Successfully Launched |date = 16 August 2016 |access-date = 17 August 2016 |website = Austrian Academy of Sciences |archive-date = 18 March 2018 |archive-url = https://web.archive.org/web/20180318054341/https://www.oeaw.ac.at/en/events-communication/public-relations-communication/public-relations-communication/ausgewaehlte-oeaw-pressemeldungen/press-releases/first-quantum-satellite-successfully-launched/ |url-status = dead }}</ref><ref name="Spacecom">{{cite web |last1=Wall |first1=Mike |title = China Launches Pioneering 'Hack-Proof' Quantum-Communications Satellite |url = http://www.space.com/33760-china-launches-quantum-communications-satellite.html |website=Space.com |publisher=Purch |access-date = 17 August 2016 |date=16 August 2016}}</ref> By October 2017, a 2,000-km fiber line was operational between [[Beijing]], [[Jinan]], [[Hefei]] and [[Shanghai]].<ref name="insidescience">{{cite web |url = https://www.insidescience.org/news/china-leader-quantum-communications |title = Is China the Leader in Quantum Communications? | author = Yuen Yiu | date=19 January 2018 |access-date=19 March 2018 |website=[[Institute of Electrical and Electronics Engineers|IEEE]]}}</ref> Together they constitute the world's first space-ground quantum network.<ref name="ieee">{{cite web |url = https://spectrum.ieee.org/china-successfully-demonstrates-quantum-encryption-by-hosting-a-video-call |title = China Demonstrates Quantum Encryption By Hosting a Video Call | author = Amy Nordrum |date=3 October 2017 |access-date=17 March 2018 |website=[[Institute of Electrical and Electronics Engineers|IEEE]]}}</ref> Up to 10 Micius/QUESS satellites are expected,<ref name="sciencenews">{{cite web |url = https://www.sciencenews.org/article/global-quantum-communication-top-science-stories-2017-yir |title = A quantum communications satellite proved its potential in 2017 | author = Jian-Wei Pan |date=3 October 2017 |access-date=19 March 2018 |website=[[Science News]]}}</ref> allowing a European–Asian [[Quantum network|quantum-encrypted network]] by 2020, and a global network by 2030.<ref name="Xinhua">{{cite news|url=http://news.xinhuanet.com/english/2016-08/16/c_135604287.htm |archive-url=https://web.archive.org/web/20160817155904/http://news.xinhuanet.com/english/2016-08/16/c_135604287.htm |url-status=dead |archive-date=17 August 2016 |title=China Focus: China's space satellites make quantum leap |author=huaxia|date=16 August 2016|access-date=17 August 2016|publisher=Xinhua}}</ref><ref name="PopSci">{{cite news|url=http://www.popsci.com/chinas-quantum-satellite-could-change-cryptography-forever|title=China's Quantum Satellite Could Change Cryptography Forever|author1=Jeffrey Lin |author2=P.W. Singer |author3=John Costello |date=3 March 2016|access-date=17 August 2016|newspaper=Popular Science}}</ref>

==== Tokyo QKD Network ====
The Tokyo QKD Network<ref>{{Cite web|url=http://www.uqcc2010.org/highlights/index.html|title=UQCC2010 - Updating Quantum Cryptography and Communications 2010 &#124; Tokyo QKD Network|website=www.uqcc2010.org}}</ref> was inaugurated on the first day of the UQCC2010 conference. The network involves an international collaboration between 7 partners; [[NEC]], [[Mitsubishi Electric]], [[Nippon Telegraph and Telephone|NTT]] and [[National Institute of Information and Communications Technology|NICT]] from Japan, and participation from Europe by Toshiba Research Europe Ltd. (UK), Id Quantique (Switzerland) and All Vienna (Austria). "All Vienna" is represented by researchers from the [[Austrian Institute of Technology]] (AIT), the [[Institute for Quantum Optics and Quantum Information]] (IQOQI) and the [[University of Vienna]].

==== Los Alamos National Laboratory ====
A hub-and-spoke network has been operated by Los Alamos National Laboratory since 2011. All messages are routed via the hub. The system equips each node in the network with quantum transmitters—i.e., lasers—but not with expensive and bulky photon detectors. Only the hub receives quantum messages. To communicate, each node sends a one-time pad to the hub, which it then uses to communicate securely over a classical link. The hub can route this message to another node using another one time pad from the second node. The entire network is secure only if the central hub is secure. Individual nodes require little more than a laser: Prototype nodes are around the size of a box of matches.<ref>{{cite arXiv|eprint=1305.0305|last1=Hughes|first1=Richard J.|last2=Nordholt|first2=Jane E.|author2-link=Beth Nordholt|last3=McCabe|first3=Kevin P.|last4=Newell|first4=Raymond T.|last5=Peterson|first5=Charles G.|last6=Somma|first6=Rolando D.|title=Network-Centric Quantum Communications with Application to Critical Infrastructure Protection|class=quant-ph|year=2013}}</ref>

==== Singapore's National Quantum-Safe Network Plus (NQSN+) ====
Following the successful [http://www.nqsn.sg National Quantum-Safe Network] Testbed trials, National Quantum-Safe Network Plus (NQSN+) was launched by IMDA in 2023 and is part of Singapore's Digital Connectivity Blueprint, which outlines the next bound of Singapore's digital connectivity to 2030. NQSN+ will support network operators to deploy quantum-safe networks nationwide, granting businesses easy access to quantum-safe solutions that safeguard their critical data. The NQSN+ will start with two network operators, Singtel and SPTel, together with SpeQtral. Each will build a nationwide, interoperable quantum-safe network that can serve all businesses. Businesses can work with NQSN+ operators to integrate quantum-safe solutions such as Quantum Key Distribution (QKD) and Post-Quantum Cryptography (PQC) and be secure in the quantum age.<ref>{{cite web | url = https://www.imda.gov.sg/about-imda/emerging-technologies-and-research/national-quantum-safe-network-plus | website = imda.gov.sg | title =  Singapore's National Quantum-Safe Network Plus (NQSN+) | first = IMDA | last = Singapore | date = 21 August 2024}}</ref>

==== Eagle-1 ====

In late 2025 or 2026, the [[European Space Agency|ESA]] plans to launch the satellite Eagle-1, an experimental space-based quantum key distribution system.<ref>{{cite web | url = https://www.esa.int/Applications/Connectivity_and_Secure_Communications/Eagle-1 | website = esa.int | title = Eagle-1 |access-date = 4 March 2025}}</ref>