QUANTUMNETWORKWHITE PAPER- English version -2021

Copyright © 2021 NICT All Rights Reser ved.

2035

CHAPTER 1:INTRODUCTION・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・ 3
1.BACKGROUND OF THE WHITE PAPER・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・3(1) Objective ・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・3(2) Overview of the White Paper・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・3(3) Discussion team and schedule・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・3
2.INTERNATIONAL TRENDS AND AN OVERVIEW OF QUANTUM INFORMATION COMMUNICATIONS・・・・3(1) Overview of quantum information communications ・・・・・・・・・・・・・・・・・・・・・・・・・・・・3(2) Policies and R&D trends regarding quantum ICT・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・4(3) Quantum cryptography ・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・6(4) Quantum network ・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・7(5) Quantum Internet・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・8
CHAPTER 2:IMAGE AND USE CASES OF QUANTUM NETWORKS IN SOCIETY・・・・・・10
1.IMAGE OF SOCIETY WITH QUANTUM NETWORKS ・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・10(1) Overview ・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・10
2.IMAGE OF SOCIETY AND USE CASES REALIZED BY QUANTUM KEY DISTRIBUTION (QKD) NETWORKS ・・・・11(1) Information to be protected by the QKD network ・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・11(2) Image of society and use cases realized by QKD ・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・11(3) Examples of use cases in individual fields ・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・12
3.IMAGE OF SOCIETY AND USE CASES REALIZED BY QUANTUM NETWORKS ・・・・・・・15(1) Image of society and use cases・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・15(2) Examples of use cases in specific fields ・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・16
CHAPTER 3:QUANTUM NETWORK EVOLUTION ・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・18
1.IMAGE AROUND THE YEAR 2025 ・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・18
2.IMAGE AROUND THE YEAR 2030 ・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・18
3.IMAGE AROUND THE YEAR 2040 ・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・19
CHAPTER 4:KEY TECHNOLOGIES AND REQUIREMENTS・・・・・・・・・・・・・・・・・・・・・・・21
1.OVERVIEW OF QUANTUM NETWORK TECHNOLOGY・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・21(1) Overview of key technologies ・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・21(2) Initiatives at NICT・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・23
2.KEY TECHNOLOGIES AND REQUIREMENTS ・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・24(1) Quantum key distribution (QKD) network ・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・24(2) Satellite and FSO communications・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・29(3) Quantum network ・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・31
CHAPTER 5:R&D ROADMAP・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・37
CHAPTER 6:PROMOTION STRATEGY・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・39
1.OVERVIEW・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・39
2.INDIVIDUAL PROMOTION STRATEGIES・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・39(1) Research and development・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・39(2) Social implementation・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・40(3) International cooperation ・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・40(4) System design・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・41(5) Human resource development・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・41
CHAPTER 7:CONCLUSION・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・43
AUTHORS AT NICT・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・43

Chap.1
INTRODUCTION
Chap.2IMAGE AND USE CASES OF
QUANTUM NETWORKS IN SOCIETY
Chap.3
QUANTUM NETWORKEVOLUTION
Chap.401

CHAPTER.1
INTRODUCTION

1. Background of the White Paper(1) Objective･ Efforts are under way in Japan and overseas to develop quantum cryptography and quantum networks,
with the ultimate goal of achieving the “Quantum Internet.” In January 2020, the Japanese government
released the “Quantum Technology Innovation Strategy.” NICT has been promoting cutting-edge R&D
related to quantum networks, and, as the “Quantum Security Hub” in the government’s strategy, started
work in FY2020 on creating a hub for industry-academia-government collaboration and developing
human resources.
･ This White Paper describes the direction of NICT’s research and development as the hub of quantum
security and the issues to be tackled in the future, in order to attract international researchers, promote
cooperation with international research institutes, and accelerate research and development of quantum
networks.

(2) Overview of the White Paper

KEY TECHNOLOGIESAND REQUIREMENTS･ This White Paper outlines international trends in quantum communication, an image of society andpotential examples of quantum networks, and an R&D roadmap and NICT’s promotion strategy to realize
such a society and examples of use. This is the first edition of the White Paper.
･ The ultimate goal is to achieve the Quantum Internet. In order to understand the importance ofcollaboration among various stakeholders in Japan and overseas, as well as research and development
efforts, this paper is intended for various readers, including governments, companies, universities, andresearch institutions.

Chap.5
R&D ROADMAP(3) Discussion team and schedule･ This White Paper was the result of discussions among NICT researchers in the fields of quantum ICT,
future ICT, space communications, and networks, as well as NICT officials working on the promotion ofquantum networks, over a period of 5 months from November 2020 to March 2021.

Chap.6PROMOTION STRATEGY(1) Overview of quantum information communications
・ Information and communications technology, such as the Internet, supports the development of the
global economy and society, and is a source of industrial competitiveness.
・The digital transformation (DX) is continuing even amid the Covid-19 pandemic, leading to social change
through the use of information and communications networks.
・ However, cyber-attacks on information and communications networks continue to increase, andCONCLUSION

therefore secure information and communications infrastructure is required.
・ It is feared that the latest cryptography used in modern information and communications networks

Chap.1 INTRODUCTION

Chap.7

2. International trends and an overview of quantum information communications

03

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INTRODUCTION

01

CHAPTER.1
INTRODUCTION

will be broken by high-performance quantum computers being developed by major IT companies in
Chap.2the United States. The National Institute of Standards and Technology (NIST) in the United States is

IMAGE AND USE CASES OF
QUANTUM NETWORKS IN SOCIETY

investigating and evaluating post-quantum cryptography. There is also the risk that attackers could be

Chap.3

capturing encrypted data flowing through existing information and communications networks, intending
to decrypt the data when high-performance quantum computers become available (harvest now, decrypt
later).
・ For this reason, quantum cryptography is required to realize “information-theoretic security” thatcannot be decrypted by any computer in principle. Several countries such as the United States, European
countries, China and Japan, are rapidly conducting R&D, demonstrating practical applications, andconstructing quantum cryptography networks for actual operation.

QUANTUM NETWORKEVOLUTION

・The Beyond 5G/6G, for which R&D activities have started in various countries around the world, includes“ultra-security and reliability” as one of its functional requirements, and quantum cryptography is
expected to play an important role here as well.
・ Research and development of quantum computing and quantum sensing technologies are currently
under way in Japan and overseas. In the future, these technologies are expected to be put into practicaluse and connected to quantum networks, enabling ultra-large-scale information processing and ultra-

Chap.4
KEY TECHNOLOGIESAND REQUIREMENTS
Chap.5high-precision information collection (see Chapter 2). Basic research is being conducted in Europe andthe United States with the aim of creating the so-called “Quantum Internet,” in which quantum information
devices are connected to quantum networks.
・The Quantum Internet is expected to become a new social infrastructure that provides new applications
and services never seen before. Research and development of quantum networks and efforts toimplement quantum networks in society have become important initiatives that are directly linked toensuring national economic and social prosperity as well as national security.

R&D ROADMAP(2) Policies and R&D trends regarding quantum ICT・ Other countries such as the United States, European countries, and China have formulated R&D
strategies for quantum information communications, including quantum key distribution and quantum
networks, as strategic core technologies, and are making large-scale R&D investments. In addition, thesecountries are promoting strategic initiatives such as forming R&D hubs and developing human resources.

・ In the United States, based on the “National Initiative Act” (2018), the Department of Energy (DOE)

PROMOTION STRATEGY[1] Policy and R&D trends in the United States

Chap.6and the National Science Foundation (NSF) are investing $1.2 billion over five years in research
approach. In this context, the DOE and the NSF are collaborating with universities, companies, andother organizations to promote research, development, and demonstration of key technologies
and human resource development in order to achieve the Quantum Internet. The Office of Scienceand Technology Policy (OSTP), in its “Strategic Vision for U.S. Quantum Networks” (February2020), has identified six areas of research activity that should be targeted and focused on for the

CONCLUSION

Quantum Internet, as well as goals for the next five and 20 years. The DOE held the “Quantum
Internet Blueprint Workshop” (July 2020) to discuss the direction and milestones of research anddevelopment for the Quantum Internet.

Chap.1 INTRODUCTION

Chap.7and development of quantum information science from a long-term perspective on a science-first04

Chap.1
INTRODUCTION

01

CHAPTER.1
INTRODUCTION[2] Policy and R&D trends in Europe
Chap.2・ In Europe, the European Commission has pledged to invest €1.0 billion over five years in the

IMAGE AND USE CASES OF
QUANTUM NETWORKS IN SOCIETY“Quantum Flagship” (since 2018) to conduct R&D on quantum technologies. In March 2020, theChap.3

European Commission released the “Strategic Research Agenda on Quantum Technology” withthe ultimate goal of the Quantum Internet, which includes a roadmap for R&D, industrialization,
standardization, and human resource development. In addition, 25 countries in Europe have agreed
to develop a quantum communication infrastructure, “EuroQCI,” which would lead to the constructionof the Quantum Internet network. In addition, the Commission is promoting the construction anddemonstration of a QKD testbed through the OpenQKD project.

QUANTUM NETWORKEVOLUTION

・ European governments, including the United Kingdom, Germany, and France, are also promoting
R&D of key technologies for QKD and the Quantum Internet.
[3] Policy and R&D trends in China

・ In China, a quantum cryptography communication backbone connecting Beijing and Shanghai
and metropolitan area networks in major cities have been constructed. The total length of thequantum cryptography networks has exceeded 7,000 km as of 2018. A number of companies have

Chap.4been established to provide communication equipment, devices, and platforms. In addition, China

KEY TECHNOLOGIESAND REQUIREMENTS

launched the satellite “Mozi” in 2016 and successfully demonstrated a quantum cryptosystem
between the satellite and the earth. In January 2021, China demonstrated an integrated quantum
network between a satellite and the ground to promote the deployment of an integrated quantum
cryptography network across China.
[4] Policy and R&D trends in Japan・ In Japan, in 2018, the Cabinet Office launched the second phase of the Strategic Innovation
Chap.5Program (SIP); the Ministry of Education, Culture, Sports, Science and Technology launched the

R&D ROADMAP

Optical and Quantum Leap Flagship Program (Q-LEAP); the Ministry of Economy, Trade and Industry
launched quantum computing (quantum annealing computer, etc.); and the Ministry of Internal
Affairs and Communications started research and development of quantum cryptography for satellite
communications.
・ However, these are individual R&D initiatives undertaken by relevant ministries, agencies, andcompanies, and may not be consistent. Therefore, the “Quantum Technology Innovation Strategy”

Chap.6PROMOTION STRATEGYthe collective efforts of industry, academia, and government in Japan.
・Based on the Strategy, quantum technology is currently being studied by eight quantum technology
R&D hubs: Quantum Computer R&D Hub (RIKEN), Quantum Device R&D Hub (National Institute ofAdvanced Industrial Science and Technology (AIST)), Quantum Computer R&D Hub (University ofTokyo and Corporate Consortium), Quantum Software R&D Hub (Osaka University), Quantum Security
Hub (National Institute of Information and Communications Technology (NICT)), Quantum Material
R&D Hub (National Institute for Materials Science (NIMS)), Quantum Sensor Hub (Tokyo Institute ofTechnology), and Quantum Chemistry Hub (National Institutes for Quantum and Radiological Science

CONCLUSION

and Technology (QST)).
・ In 2020, the Cabinet Office started research and development of quantum technologies, including
quantum communications, under the “Moonshot Research and Development Program,” and theChap.1 INTRODUCTION

Chap.7(January 2020) was compiled and published to promote quantum technology innovation by mobilizing

05

Chap.1
INTRODUCTION

01

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INTRODUCTION

Ministry of Internal Affairs and Communications started research and development toward theChap.2IMAGE AND USE CASES OF
QUANTUM NETWORKS IN SOCIETY
Chap.3

creation of a global quantum cryptography network.
・ NICT, as the Quantum Security Hub, is conducting and promoting research and development of
quantum cryptography and other key technologies for quantum networks.

(3) Quantum cryptography-Outline of technology・ Quantum cryptography is a technology that uses the properties of quantum mechanics to makecryptographic communication unbreakable by any computer. It consists of two steps: quantum key

QUANTUM NETWORKEVOLUTION

distribution (QKD) and one-time pad encryption. QKD is a method of sharing symmetric cryptographic
keys between two remote locations without revealing any information to a third party (eavesdropper)
with any theoretical ability. In one-time pad encryption, a cryptographic key of the same size as the data(plaintext) is prepared, and a ciphertext is generated by the XOR of the plain text and the cryptographic
key. The cryptographic key is discarded each time, without reusing it. In this way, cryptographic
communications with “information-theoretic security” that cannot be deciphered in principle by any

Chap.4computer, including quantum computers, can be realized.

KEY TECHNOLOGIESAND REQUIREMENTS
Chap.5
R&D ROADMAP

Figure 1 : Mechanism of quantum cryptography
Chap.6PROMOTION STRATEGY・ The cryptography that is widely used today secures confidentiality in “computational security,” which
would require a huge amount of computing

power to decrypt. However, there is a potential threat thatdecryption will become easier in the future with the emergence of quantum computers and completely
new computing technologies and mathematical algorithms. In particular, in the case of critical informationthat requires confidentiality for decades, a malicious third party may launch a so-called “harvest now,
decrypt later” attack, in which encrypted data is eavesdropped and obtained for the time being, without
having the technology to decrypt it, and the encrypted data is then decrypted when new computing

CONCLUSION

technology becomes available in the future.
・ On the other hand, quantum cryptography has information-theoretic security: it cannot be decryptedin principle by any computer in the future. At present, the only cryptographic technology that can

Chap.1 INTRODUCTION

Chap.7-What kind of system? Why do we need it?-06

Chap.1
INTRODUCTION

01

CHAPTER.1
INTRODUCTION

achieve information-theoretic security is quantum cryptography, which thus offers the strongest level ofChap.2

confidentiality among currently known cryptographic technologies. Quantum cryptography can be used to

IMAGE AND USE CASES OF
QUANTUM NETWORKS IN SOCIETY

protect national secrets such as national security, and to protect information that requires ultra-long-term

Chap.3

confidentiality in fields such as medical, finance, infrastructure, and smart manufacturing.
-International trends・ Research and development and social demonstrations are progressing in countries such as Japan,
European countries, the United States, China, and South Korea, and international standardization and fullscale practical application are starting.

QUANTUM NETWORKEVOLUTION-Requirements・ It is necessary to establish a QKD network technology that allows a large number of QKD transmittersand receivers to be connected to the network and operated safely and efficiently.
・By sharing the encryption key at any two points (or multiple points) through the QKD network and using
the key at the conventional network (the classical network), security services using the informationtheoretic secure encryption key are realized.

Chap.4
KEY TECHNOLOGIESAND REQUIREMENTS(4) Quantum network-Outline of technology・ A quantum network is communication infrastructure for distributing quantum information (quantum
bits used in quantum computers, quantum entanglement state with quantum correlation, etc.) over
networks instead of classical digital information (0s and 1s), and is used for various applications.
・ Distribution of quantum information through a quantum network is expected to enable quantum

Chap.5

cryptography over longer distances than is currently possible, as well as a quantum network of optical

R&D ROADMAP

clocks (atomic clocks that generate precise optical signals) that can be connected to each other to keep
time with an accuracy that is impossible with conventional technology.
・Moreover, by connecting multiple small- and medium-scale quantum computers to a quantum network,
it would be possible to build a large-scale quantum computer with high computing power (distributed
quantum computing). Furthermore, by connecting a large-scale quantum computer at a remote location
to a quantum network, it is expected to be possible to perform secret quantum computation without

Chap.6PROMOTION STRATEGY-International trends-

・ Basic research on quantum physics, which is an key technology on a quantum network, has been
conducted around the world. In Europe and the United States, efforts to demonstrate the operation
principle in the field has started since around 2020, and in Japan, studies have started to build a testbed
on a quantum network.
-Requirements-

CONCLUSION

・ To realize a quantum network, the following key technologies

are required: quantum memory

technology for storing and processing quantum information; quantum interface technology for connecting
optical signals and quantum memory; and quantum repeater technology for relaying and transmitting

Chap.1 INTRODUCTION

Chap.7anyone knowing the contents of the computation.

07

Chap.1
INTRODUCTION

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INTRODUCTION

quantum information (especially quantum entanglement) without destroying it. All of these technologies
Chap.2are still in the basic research stage, and trial and error is still being conducted with various materials and

IMAGE AND USE CASES OF
QUANTUM NETWORKS IN SOCIETY

candidate relay methods.

Chap.3
QUANTUM NETWORKEVOLUTION
Chap.4

Figure 2 : Overview of quantum networks(5) Quantum Internet

KEY TECHNOLOGIESAND REQUIREMENTS

・Definitions of the Quantum Internet are shown in the table below in the research strategies and projects
on quantum technology in the United States and Europe.
・ The Quantum Internet is a global quantum network that connects quantum information equipment
and devices such as quantum computers and quantum sensors. Also, given that the current Internet isa network in which multiple networks are interconnected and digital information (bits) is distributed, theQuantum Internet is a network in which multiple quantum networks are interconnected and quantum

Chap.5

information (qubits) is distributed.

R&D ROADMAP・ In the future, the definition of the Quantum Internet is expected to be clarified through international
discussions as its key technologies mature.
・ When the Internet first appeared, no one imagined that it would become indispensable infrastructure
for socio-economic activities and people’s lives. Today, it is not clear what kind of network the Quantum
Internet will be and how it may be used. However, it is expected to be used for future applications andservices that cannot be imagined at present, and to make people’s lives richer, safer and more secure.

Chap.6PROMOTION STRATEGYCONCLUSION

Chap.1 INTRODUCTION

Chap.708

Chap.1
INTRODUCTION

01

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INTRODUCTION

Document/Organization

Chap.2IMAGE AND USE CASES OF
QUANTUM NETWORKS IN SOCIETY

United States”A Strategic Vision for America’s
Quantum Networks”（Feb.2020）,
National Quantum Coordination Office,White House

Chap.3
QUANTUM NETWORKEVOLUTION
Chap.4The long-term ambition of the European Quantum Internet
Alliance is to build a Quantum Internet that enables
quantum communication applications between any two
points on Earth.

“Strategic Research Agenda on Quantum Quantum Internet: quantum computers, simulators andTechnology”(Mar.2020), Quantum
sensors interconnected via quantum networks distributing
Flagship Project
information and quantum resources such as coherence andentanglement to secure our digital infrastructure.
IRTF (Internet Research Task Force)

Standardization
Body

The quantum internet—a vast network of quantum
computers and other quantum devices.

“Quantum Internet Blueprint Workshop” The international research community perceives the(Oct.2020), Department of Energy（DOE） construction of a first prototype global quantum network—
the Quantum Internet—to be within reach over the next
decade.
Quantum Internet Alliance(QIA)

EuropeExample of definition

Quantum Internet - A network of Quantum Networks. The
Quantum Internet will be merged into the Classical Internet
to form a new Hybrid Internet. The Quantum Internet may
either improve classical applications or may enable newquantum applications.

KEY TECHNOLOGIESAND REQUIREMENTS

Table 1 : Example definitions of the Quantum Internet

Chap.5
R&D ROADMAP
Chap.6PROMOTION STRATEGYCONCLUSION

Chap.1 INTRODUCTION

Chap.709

Chap.1
INTRODUCTION
Chap.2IMAGE AND USE CASES OF
QUANTUM NETWORKS IN SOCIETY
Chap.302

IMAGE AND USE CASES OF QUANTUM NETWORKS IN SOCIETY

1. Image of society with quantum networks(1) Overview･ The following are examples of use cases that are expected to be realized by quantum networks in the
future.
･ In the 2020s, QKD networks are expected to enable the secure exchange of critical information in the
medical, manufacturing, and financial fields.
･ In the 2030s and beyond, the spread of QKD networks is expected to enable the safe and secure
distribution of information in a wider variety of fields. In addition, quantum networks that interconnect

QUANTUM NETWORKEVOLUTION

with quantum computers and quantum sensors will begin to be deployed in society.
･ In the 2040s, the Quantum Internet, in which multiple quantum networks are globally connected to eachother, will be established, and entirely new applications and services will emerge. The Quantum Internet
is expected to provide the foundation for affluent lives and socioeconomic activities.

Examples of use cases

Chap.4Progress inquantum network
technology

KEY TECHNOLOGIESAND REQUIREMENTS

2030s● Administration/Diplomacy/Security : Exchangeof personal information in administration,communication of confidential in diplomacy,national security, etc.
● Life : Ultra-secure Internet at the home level
through cryptography vending machines formobile terminals to exchange of personal
medical and financial information

2040s★ Chemicals, materials, drug discovery, etc. :･ QKD ( global scale )Discovery of new materials and new drugs, etc. ･ Satellite quantum
using quantum computers connected to quantum communication
networks･ Quantum networks( global scale )▲ Disaster prevention and disaster response :Detection of weak gravity fluctuations byquantum sensors connected to quantum
networks● Resource development : High-precision imagetransmission of drilling robots on the Moon andMars ( Quantum coding beyond the Shannon
limit )

R&D ROADMAP
Chap.6･ QKD ( nationwaide→ global )･ Satellite QKD/physicallayer encryption･ Quantum networks

Quantum computing
and sensing
technologies･ NISQ Quantum Computer
IBM1
2020 : 65qubit
2021 : 127qubit
2022 : 433qubit
2023 : 1121qubit･ NISQ Quantum Computer･ Small-scale fault-tolerant
quantum computers･ Quantum sensors

PROMOTION STRATEGY･ Fault-tolerant quantum
computers･ Distributed quantum
computing･ Quantum sensors● : QKD, ★ : Quantum computer, ▲ : E quantum sensing

CONCLUSION

Table 2 : Examples of Use Cases of Quantum Networks

1. https://www.ibm.com/blogs/think/jp-ja/ibm-quantum-roadmap/

Chap.2 IMAGE AND USE CASES OF QUANTUM NETWORKS IN SOCIETY

2020s● Medical care : Exchange of biological information, ･ QKD ( Kanto region
such as electronic medical records and genome→ nationwide )information, that would have a lifetime impact if
leaked● Manufacturing : Exchange of information thatwould have a significant impact on corporate
activities due to leakage of trade secrets, knowhow, important technologies, etc.
● Finance : Exchange of information on financial
systems, transactions, etc.

Chap.5

Chap.7

CHAPTER.2

10

Chap.1
INTRODUCTION
Chap.2IMAGE AND USE CASES OF
QUANTUM NETWORKS IN SOCIETY
Chap.302

CHAPTER.2
IMAGE AND USE CASES OF QUANTUM NETWORKS IN SOCIETY

2. Image of society and use cases realized by quantum key distribution (QKD) networks(1) Information to be protected by the QKD network
・ Security, diplomacy, defense, and personal genome information, all of which would have a significant
impact if leaked, must be protected for a long time. When sending such information over a network, it isexpected that QKD, which guarantees information-theoretic security, will be used.

QUANTUM NETWORKEVOLUTION

Information holder

Examples of information to be protected

National/local
governments

・Information related to diplomacy, defense, security, geographic (infrastructure, undergroundspace), family registers/residents, voting, etc.

Organizations(enterprises, etc.)

・Customer lists, new business plans, prices, response manuals, other sales information
・New technologies, manufacturing methods, know-how, design drawings, other technicalinformation

Individuals

・Health data, genome information, ideas, beliefs, preferences, personal identification
numbers, credit card numbers, passwords, etc.

Table 3: Examples of information to be protected by QKD
Chap.4
KEY TECHNOLOGIESAND REQUIREMENTS(2) Image of society and use cases realized by QKD・ Deployment of QKD will enable theoretically secure communications in medicine, industry, services,
government, diplomacy, security, and daily life.

Chap.5
R&D ROADMAPPROMOTION STRATEGY
Chap.7
CONCLUSION

Figure 3 : Examples of use cases realized by QKD

Chap.2 IMAGE AND USE CASES OF QUANTUM NETWORKS IN SOCIETY

Chap.6

11

Chap.1
INTRODUCTION
Chap.2IMAGE AND USE CASES OF
QUANTUM NETWORKS IN SOCIETY
Chap.302

CHAPTER.2
IMAGE AND USE CASES OF QUANTUM NETWORKS IN SOCIETY(3) Examples of use cases in individual fields① Medical and financial fields – secure distribution, storage and utilization of data in the quantum securecloud【 Background and necessity 】

・It is important to store large amounts of information, which is an important management resourceof a company, using encryption and other methods, and to decrypt them properly when necessary.
・ At present, communication can be secured by current encryption technology. However, with theadvancement of quantum computers, there is a risk that the encryption used for highly secure

QUANTUM NETWORKEVOLUTION

information communication for electronic payments and the exchange of personal information will
be broken. Therefore, encryption technology that can never be broken is required.
【 Outline of technology 】

・ Quantum secure cloud technology is a cloud technology that enables the secure distribution,
storage, and utilization of data by integrating quantum cryptographic technology, secret sharing

Chap.4technology, and post-quantum cryptographic technology. QKD networks and secret sharing enable

KEY TECHNOLOGIESAND REQUIREMENTS

information-theoretically secure data storage and communication. The authentication infrastructure(post-quantum/public key authentication infrastructure) based on post-quantum cryptography, which
requires enormous computational power to decipher, is used to authenticate users on the network
and issue signatures to prevent tampering.
・ The establishment of quantum secure cloud technology will not only ensure high security thatprevents tampering and decryption, but will also enable the collection, analysis, processing, and useof highly confidential data, such as personal and corporate information accumulated in the medical,

Chap.5new materials, manufacturing, and financial fields.

R&D ROADMAPPROMOTION STRATEGY
Chap.7
CONCLUSION

Figure 4 : Mechanism of quantum secure cloud technology

Chap.2 IMAGE AND USE CASES OF QUANTUM NETWORKS IN SOCIETY

Chap.612

Chap.1
INTRODUCTION

02

CHAPTER.2
IMAGE AND USE CASES OF QUANTUM NETWORKS IN SOCIETY② Administration, diplomacy and security – Secure backbone network with satellite QKD
Chap.2IMAGE AND USE CASES OF
QUANTUM NETWORKS IN SOCIETY
Chap.3【 Background and necessity 】
・ The QKD network needs to spread widely across Japan and other countries in order to securely
exchange information related to national security and confidentiality, as well as personal information
held by local governments.
・ However, QKD is inherently vulnerable to signal attenuation, which makes long-distancetransmission of quantum cryptography using optical fiber difficult. Therefore, satellite-based
quantum cryptography communications networks in space, in which signal attenuation is less thanthat of optical fibers, will play an important role in realizing a global-scale QKD network.

QUANTUM NETWORKEVOLUTION【 Outline of technology 】

・ In addition to the link between geostationary-orbit satellites and the ground, the QKD backbone
network based on satellite QKD enhances robustness and availability by utilizing multiple satellites(constellation satellites) in low- and medium-earth orbit and cooperation with the terrestrial QKD
network.

Chap.4・ In the future, it is expected to play a role as infrastructure for exploration and development by

KEY TECHNOLOGIESAND REQUIREMENTS

establishing quantum communication links with the Moon and Mars.

Chap.5
R&D ROADMAPPROMOTION STRATEGY
Chap.7

Figure 5 : Secure backbone network with satellite QKD③ Industry and service area – Local secure network by optical space communication【 Background and necessity 】

CONCLUSION

・ The trade secrets, know-how, and technical information that companies in the industrial andservice sectors have accumulated over many years are important information. One way to preventthe information leakage this information by industrial espionage is to use a local secure network

Chap.2 IMAGE AND USE CASES OF QUANTUM NETWORKS IN SOCIETY

Chap.613

Chap.1
INTRODUCTION

02

CHAPTER.2
IMAGE AND USE CASES OF QUANTUM NETWORKS IN SOCIETY

based on free space optical (FSO) communication, which can be built independently by companies on
Chap.2IMAGE AND USE CASES OF
QUANTUM NETWORKS IN SOCIETY
Chap.3the scale of their premises, office buildings, and major branch offices.
【 Outline of technology 】

・ A secure network that can be built independently by companies must be able to be: (1) built
independently of external organizations, and (2) built at low cost. Among several QKD protocols, CVQKD (Continuous Variable - Quantum Key Distribution), a system that is expected to be able to bebuilt at low cost using the equipment and components used in current optical communications, canbe implemented in FSO communications. By implementing this system in FSO communications, asecure network that satisfies the above requirements can be built without procuring and installing

QUANTUM NETWORKEVOLUTION

new optical fibers. In addition, by combining this system with physical layer cryptography( see
Chapter 4), which utilizes a unique characteristic of FSO communications, namely that the spatial
divergence of laser light is narrower than that of radio waves, making it difficult for third parties toeavesdrop, it is possible to build a network that can meet various user requirements.

Chap.4
KEY TECHNOLOGIESAND REQUIREMENTS
Chap.5
R&D ROADMAP

Figure 6 : Local secure network with QKD and physical layer encryption④ Daily life – Highly secure infrastructure available to everyone

・ As services via mobile devices become more prevalent in people’s lives due to the emergence

Chap.6PROMOTION STRATEGY
Chap.7of 5G technology, personal security risks such as leakage of important information in everyday life
(e.g., passwords, credit card numbers, and health information) and takeover of smart devices (e.g.,
network cameras, smart appliances, and smart speakers) will emerge. In order to ensure security at
the individual level, greater consideration is required to avoid security level gap between individuals
and organizations such as security providers.
・ Therefore, the security technology used in the current security infrastructure is required to be
updated.
【 Outline of technology 】

CONCLUSION

・ In this infrastructure, key exchange and authentication on a classical network is carried out by
post-quantum cryptography that is difficult to break even by quantum computers. Communication
between a mobile terminal and an access point is carried out by physical layer cryptography,

Chap.2 IMAGE AND USE CASES OF QUANTUM NETWORKS IN SOCIETY【 Background and necessity 】

14

Chap.1
INTRODUCTION

02

CHAPTER.2
IMAGE AND USE CASES OF QUANTUM NETWORKS IN SOCIETY

enhancing the security of networks. Since these technologies can be implemented as algorithms on
Chap.2

mobile terminals, individuals can use this infrastructure easily.

IMAGE AND USE CASES OF
QUANTUM NETWORKS IN SOCIETY
Chap.3
QUANTUM NETWORKEVOLUTION
Chap.4

Figure 7 : New security infrastructure with post-quantum cryptography infrastructure

KEY TECHNOLOGIESAND REQUIREMENTS

3. Image of society and use cases realized by quantum networks(1) Image of society and use cases
・ The realization of quantum networks (the Quantum Internet) is expected to lead to safe, secure andChap.5convenient lifestyles and advanced socioeconomic activities.

R&D ROADMAP
Chap.2 IMAGE AND USE CASES OF QUANTUM NETWORKS IN SOCIETY

Chap.6PROMOTION STRATEGY
Chap.7
CONCLUSION

Figure 8 : Examples of society and use cases realized by quantum networks

15

Chap.1
INTRODUCTION
Chap.2IMAGE AND USE CASES OF
QUANTUM NETWORKS IN SOCIETY
Chap.302

CHAPTER.2
IMAGE AND USE CASES OF QUANTUM NETWORKS IN SOCIETY(2) Examples of use cases in specific fields① Quantum sensing – disaster prevention and disaster response【 Background and necessity 】

・ By connecting optical clocks (an example of quantum sensors), which can provide high-precision
timing and local gravity sensing, to a quantum network, and sending measurements of gravity
field fluctuations caused by, for example, earthquakes, volcanic eruptions, and landslides, via thequantum network, it will be possible to issue disaster warnings earlier than before.

QUANTUM NETWORKEVOLUTION・In addition, highly accurate space and time synchronization is expected to lead to the emergence ofnext-generation communication systems and new businesses that utilize time.
【 Outline of technology 】

・In order to transmit information such as gravitational field fluctuations detected by an optical clockusing a quantum network, a technology called “coherent link” is needed. A coherent link comparesand synchronizes optical clocks by connecting their optical frequencies as light waves. A quantum

Chap.4

network of optical clocks will enable the fastest measurement of the optical frequencies of the clocks

KEY TECHNOLOGIESAND REQUIREMENTS

allowed by physics by adding it to the coherent link.
・ In addition to the coherent link, other key technologies such as optical clocks capable of quantum
gate operation, quantum interfaces with photons, and two-photon interference will be required.

Chap.5
R&D ROADMAPPROMOTION STRATEGY
Chap.7

Figure 9 : Use cases of quantum networks for optical clocks② Distributed quantum computing – chemistry, materials, drug discovery, etc.
【 Background and necessity 】

・ Quantum computers will make it possible to simulate ultra-large-scale molecular structures,
which has been difficult with conventional supercomputers, and are expected to lead to drug
discovery, materials with new functionalities, and new use cases for future social infrastructure.

CONCLUSION

・ Furthermore, by connecting quantum computers to a quantum network, it will be possible toaccelerate the development of large-scale quantum computers.
・ Since such large-scale quantum computation is expected to be provided by cloud services, aChap.2 IMAGE AND USE CASES OF QUANTUM NETWORKS IN SOCIETY

Chap.616

Chap.1
INTRODUCTION

02

CHAPTER.2
IMAGE AND USE CASES OF QUANTUM NETWORKS IN SOCIETY

method of performing quantum computation while keeping the computation secret is required. By
Chap.2using a small-scale quantum computer connected to a large-scale quantum computer by a quantum

IMAGE AND USE CASES OF
QUANTUM NETWORKS IN SOCIETY

network, such blind quantum computation is expected to be possible.

Chap.3【 Outline of technology 】

・Quantum computing is a computational method that uses quantum bits (qubits) based on quantum
physics instead of classical digital bits (0s and 1s) to rapidly solve certain computational problems
with computational resources that grow exponentially with the number of qubits (called “Hilbert
space”). Distributed quantum computing is a method of extending quantum computing by connecting
quantum computers in a quantum network.

QUANTUM NETWORKEVOLUTION

・ In order to connect quantum computers at the qubit level in a quantum network, a wide range oftechnologies is required. These include quantum repeaters and quantum network technologies forsharing quantum entangled states over optical fibers, as well as technologies for constructing smalland medium-scale quantum computers.

Chap.4
KEY TECHNOLOGIESAND REQUIREMENTS
Chap.5Figure 10 : Use cases for distributed quantum computer networks

R&D ROADMAPPROMOTION STRATEGY
Chap.7
CONCLUSION

Chap.2 IMAGE AND USE CASES OF QUANTUM NETWORKS IN SOCIETY

Chap.617

Chap.1
INTRODUCTION

03

CHAPTER.3
QUANTUM NETWORK EVOLUTION･ Quantum networks using QKD and quantum repeaters will be introduced in stages as the technology

IMAGE AND USE CASES OF
QUANTUM NETWORKS IN SOCIETY･ This chapter describes the predicted evolution of quantum networks by the 2025s, 2030s, and 2040s.
Chap.2is developed and implemented. However, this does not mean that conventional networks such as theChap.3

Internet and cell phone networks (classical networks) will be replaced by quantum networks, but rather
that classical networks and quantum networks will coexist. Such coexistence will enable the various
services described in the previous chapter. The following is an overview of the predicted evolution ofquantum networks.

QUANTUM NETWORKEVOLUTION

1. Image around the year 2025
・ The quantum key distribution (QKD) network between the ground and satellites will start operation,
providing a secure communication service. Services using quantum computing and quantum sensing
using classical networks will also be launched.

Chap.4
KEY TECHNOLOGIESAND REQUIREMENTS
Chap.5
R&D ROADMAP
Chap.6

2. Image around the year 2030
・The operation of QKD networks connecting the ground and satellites by secure communication services

CONCLUSION

will expand. Services using quantum computing, quantum measurement and sensing over classicalnetworks will also expand.

2. PKI: Public Key Infrastructure, TLS: Transport Layer Security (a mechanism for ensuring a secure communication path for communication on the Internet)

Chap.3 QUANTUM NETWORK EVOLUTIONPROMOTION STRATEGY
Chap.7

Figure 11 : Evolution of quantum networks around 2025 2

18

Chap.1
INTRODUCTION

03

CHAPTER.3
QUANTUM NETWORK EVOLUTION

Chap.2IMAGE AND USE CASES OF
QUANTUM NETWORKS IN SOCIETY
Chap.3
QUANTUM NETWORKEVOLUTION
Chap.4
KEY TECHNOLOGIESAND REQUIREMENTS

Figure 12 : Evolution of quantum networks around 2030

3. Image around the year 2040
・A global quantum network of satellites and terrestrial networks will be established, and virtual quantum

Chap.5

network services will be realized, accommodating a wide variety of quantum networks and protocols.

R&D ROADMAP
Chap.6

CONCLUSION

Figure 13 : Evolution of quantum networks around 2040

Chap.3 QUANTUM NETWORK EVOLUTIONPROMOTION STRATEGY
Chap.719

Chap.1
INTRODUCTION

03

CHAPTER.3
QUANTUM NETWORK EVOLUTION・ Infrastructure providers and quantum virtual network operators (VNOs) will construct virtual quantum
Chap.2

networks and provide services to meet the needs of application/content providers using quantum

IMAGE AND USE CASES OF
QUANTUM NETWORKS IN SOCIETY

networks around 2040.

Chap.3
QUANTUM NETWORKEVOLUTION
Chap.4
KEY TECHNOLOGIESAND REQUIREMENTS

Figure 14 : Image of quantum network services around 2040

Chap.5
R&D ROADMAP
Chap.6

CONCLUSION

Chap.3 QUANTUM NETWORK EVOLUTIONPROMOTION STRATEGY
Chap.720

Chap.1
INTRODUCTION
Chap.204

CHAPTER.4
KEY TECHNOLOGIES AND REQUIREMENTS

1. Overview of quantum network technology

IMAGE AND USE CASES OF
QUANTUM NETWORKS IN SOCIETY(1) Overview of key technologies
・ The chart below shows the key technologies of quantum networks in the “Quantum Technology
Innovation Strategy” (January 2020). Of these, NICT is conducting R&D on the technologies shown in red.

Chap.3
QUANTUM NETWORKEVOLUTION
Chap.4
KEY TECHNOLOGIESAND REQUIREMENTS
Chap.5
R&D ROADMAP
Chap.6

CONCLUSION

Chap.4 KEY TECHNOLOGIES AND REQUIREMENTSPROMOTION STRATEGY
Chap.721

KEY TECHNOLOGIES AND REQUIREMENTS

INTRODUCTION

IMAGE AND USE CASES OF
QUANTUM NETWORKS IN SOCIETYQUANTUM NETWORKEVOLUTION

KEY TECHNOLOGIESAND REQUIREMENTS

R&D ROADMAPCONCLUSION

Chap.4 KEY TECHNOLOGIES AND REQUIREMENTSPROMOTION STRATEGY

Chap.7

CHAPTER.4

04
Chap.1

Chap.2

Chap.3

Chap.4

Chap.5

Chap.622

Chap.1
INTRODUCTION

04

CHAPTER.4
KEY TECHNOLOGIES AND REQUIREMENTS

Chap.2IMAGE AND USE CASES OF
QUANTUM NETWORKS IN SOCIETY
Chap.3
QUANTUM NETWORKEVOLUTION
Chap.4
KEY TECHNOLOGIESAND REQUIREMENTS

Figure 15 : Overview of quantum network technologies
Chap.5
R&D ROADMAP(2) Initiatives at NICT・ NICT is conducting R&D on quantum key distribution (QKD) networks, satellite and spacecommunications, and quantum networks. The next section gives an overview of these key technologies
and requirements.

Chap.6

CONCLUSION

Chap.4 KEY TECHNOLOGIES AND REQUIREMENTSPROMOTION STRATEGY
Chap.723

Chap.1
INTRODUCTION

04

CHAPTER.4
KEY TECHNOLOGIES AND REQUIREMENTS

Chap.2IMAGE AND USE CASES OF
QUANTUM NETWORKS IN SOCIETY
Chap.3
QUANTUM NETWORKEVOLUTION

Figure 16 : R&D on quantum network technologies at NICT
Chap.4
KEY TECHNOLOGIESAND REQUIREMENTS

2. Key technologies and requirements(1) Quantum key distribution (QKD) network【 Overview 】

・ A QKD network is a technology that makes it possible to share cryptographic keys with any

Chap.5two (or more) points in a network. The cryptographic keys shared in a QKD network are used for

R&D ROADMAP

cryptographic communications in conventional networks(the Internet, mobile communications

network, etc.) in which several application services are provided. In other words, by adding a QKD
network to a conventional network, it is possible to provide a secure cryptographic key for a very
long time. One of the applications of the QKD network is quantum secure cloud technology.
【 Required technologies 】

Chap.6such as key management/key relay and QKD network control/management are required. In addition,
it is necessary to establish node security (trusted nodes).
【 International trends 】

・ Demonstrations and test operations are under way in the United States, Europe, China, and South
Korea, as well as Japan. The Tokyo QKD Network, a testbed built in 2010 by Japanese companies,
has been operating the longest in the world.
As for QKD modules, ID Quantique (Switzerland), Quantum CTek (China), Toshiba (Japan) and others

CONCLUSION

have started commercialization and operation, and NEC (Japan) is now conducting field tests. In
addition, a number of start-ups are developing QKD devices in various countries. QKD network
services are also being commercialized by companies such as CAS Quantum Network (China) andChap.4 KEY TECHNOLOGIES AND REQUIREMENTSPROMOTION STRATEGY
Chap.7・In addition to QKD devices (QKD transmitters and receivers, called QKD modules), key technologies

24Chap.1
INTRODUCTION

04

CHAPTER.4
KEY TECHNOLOGIES AND REQUIREMENTS

Quantum Xchange (USA). Incumbent telecommunications companies such as BT (UK), Verizon (USA),
Chap.2and SK Telecom (Korea) are also entering the market.

IMAGE AND USE CASES OF
QUANTUM NETWORKS IN SOCIETY
Chap.3
QUANTUM NETWORKEVOLUTION
Chap.4
KEY TECHNOLOGIESAND REQUIREMENTS

Figure 17 : QKD network configuration【 Reference 】International standardization of QKD network technology

・ NICT is actively promoting international standardization at the International Telecommunication
Union Telecommunication Standardization Sector (ITU-T) and the International Organization forStandardization/International Electrotechnical Commission (ISO/IEC) to promote the global spread of
QKD network technology in cooperation with governments and companies.

Chap.5・ In October 2019, ITU-T published “Y.3800: Overview on networks supporting quantum key

R&D ROADMAP

distribution,” the first international standard recommendation in the field of quantum cryptography,
adopting the basic specifications of the Tokyo QKD network. Starting with this recommendation,
ITU-T has published more than 10 recommendations. Japan is also leading the development of theserecommendations.
・ At ISO/IEC JTC1, NICT is actively participating in the development of standards for the safetyassessment of QKD devices. Since QKD devices are security devices, it is necessary to develop safety

Chap.6that commercialized QKD devices are implemented and operated correctly from the viewpoint ofsafety, in order to properly distribute QKD devices in the market.

CONCLUSION

Chap.4 KEY TECHNOLOGIES AND REQUIREMENTSPROMOTION STRATEGY
Chap.7and operational guidelines, as well as a framework for evaluation, testing, and certification to ensure

25

Chap.1
INTRODUCTION

04

CHAPTER.4
KEY TECHNOLOGIES AND REQUIREMENTS

Chap.2IMAGE AND USE CASES OF
QUANTUM NETWORKS IN SOCIETY
Chap.3
QUANTUM NETWORKEVOLUTION
Chap.4

Figure 18 : Basic configuration of the QKD network specified in ITU-T Y.3800 3

KEY TECHNOLOGIESAND REQUIREMENTS

・ The key technologies required for QKD networks, their applications, quantum secure cloud technology
are outlined below.
① Quantum key distribution (QKD)【 Outline of technology 】

Chap.5・This technology is used to share encryption keys between two distant parties using photons, which

R&D ROADMAP

are particles of light. Due to the uncertainty principle of quantum mechanics, any eavesdropping attack
on photons can be detected without fail. By using cryptographic keys that cannot be eavesdropped,
information-theoretic secure cryptographic keys can be generated. On the other hand, since photons
are extremely weak signals and ordinary optical communication relay amplifiers destroy thequantum state of photons, the distance over which a QKD transmitter/receiver pair can generate a
key is currently limited to 50–100 km at the most.

Chap.6【 Outline of technology 】

・ Key management is a technology that securely manages keys generated by QKD modules andappropriately supplies them to applications. Key relay is a technology that securely transmits keys
generated by a QKD module to remote nodes through one-time pad encryption and a cryptographic
key generated by another QKD module. By combining these technologies with nodes with guaranteed
security (trusted nodes), long-distance key generation and QKD networking, which are impossible

CONCLUSION

with a single QKD transmitter and receiver, are realized.

3. QKDN: QKD Network, KM: Key Manager

Chap.4 KEY TECHNOLOGIES AND REQUIREMENTSPROMOTION STRATEGY
Chap.7② Key management and key relay technology

26

Chap.1
INTRODUCTION

04

CHAPTER.4
KEY TECHNOLOGIES AND REQUIREMENTS

Chap.2IMAGE AND USE CASES OF
QUANTUM NETWORKS IN SOCIETY
Chap.3
QUANTUM NETWORKEVOLUTION

Figure 19 : Key relay mechanism in QKD network③ QKD network control and management technology【 Outline of technology 】

・ The QKD network control technology is comprised of session control between sending andChap.4
KEY TECHNOLOGIESAND REQUIREMENTS
Chap.5receiving hosts, access control, key relay routing and rerouting, policy control, network configuration
control, etc. in the QKD network. The QKD network management technology appropriately manages
the entire network by monitoring the status of network components and links in the QKD network.
It is expected that conventional network control and management technologies, such as network
virtualization/automation technology and information-centric networking technology, can be applied
to the QKD network in various ways and thus enable the network to efficiently deliver cryptographic
keys with the required size and security level to users at any time.
④ Quantum secure cloud technology

R&D ROADMAP【 Outline of technology 】

・ This technology enables data backup storage and computation processing that cannot be
deciphered or tampered by any computer, by integrating quantum cryptography, secret sharing,post-quantum/public key authentication infrastructure, and secure computing. Multiple data servers
are connected by secret channel using quantum cryptography to form a storage network, and secret

Chap.6

storage of the original data.
・In this way, the system provides both confidentiality, in which the original data cannot be recovered
even if information is stolen from some of the data servers, and availability, in which the user canrecover the original data by collecting distributed data from the remaining data servers in case someof the data servers are lost due to a disaster.
・ In addition, it enables secure secondary use of the data, since it is possible to realize securecomputing by processing the data contained in the meaningless distributed data.
・ User authentication and data falsification prevention are performed using certificates with digital

CONCLUSION

signatures issued by the post-quantum - public key authentication infrastructure. This infrastructureis one of the next-generation cryptographic infrastructures that are expected to spread in the futureand is based on computational security. For user authentication and prevention of data falsification

Chap.4 KEY TECHNOLOGIES AND REQUIREMENTSPROMOTION STRATEGY
Chap.7sharing algorithms are implemented on the network to realize information-theoretic secure backup

27

Chap.1
INTRODUCTION

04

CHAPTER.4
KEY TECHNOLOGIES AND REQUIREMENTS

on quantum secure clouds, the post-quantum - public key authentication infrastructure is used
Chap.2

because it is sufficient to secure security within the time required for processing.

IMAGE AND USE CASES OF
QUANTUM NETWORKS IN SOCIETY・ In this way, the entire system is configured by combining appropriate security technologies
according to safety and convenience.

Chap.3
QUANTUM NETWORKEVOLUTION
Chap.4
KEY TECHNOLOGIESAND REQUIREMENTS

Figure 20 : Quantum secure cloud technology
Chap.5
R&D ROADMAP【 What kind of system? Why do we need it? 】

・ This technology is necessary to ensure ultra-long-term confidentiality of data, including medical
information such as patient information and genetic data. On the other hand, there is concern aboutdata loss due to disasters, etc., in case such data is stored in only one hospital. It is also crucial tosafely back up data in remote locations. The quantum secure cloud can meet both these needs. (See“Mechanism of quantum secure cloud technology” on p. 20.)

Chap.6

・This is a unique Japanese technology that is being demonstrated by NICT and companies.

【 Requirements 】

・ It is necessary to appropriately integrate the QKD network and various modern security
technologies (secret distribution, secret calculation, electronic signatures, etc.) into a system.

CONCLUSION

Chap.4 KEY TECHNOLOGIES AND REQUIREMENTSPROMOTION STRATEGY
Chap.7【 International trends 】

28

Chap.1
INTRODUCTION
Chap.2IMAGE AND USE CASES OF
QUANTUM NETWORKS IN SOCIETY
Chap.304

CHAPTER.4
KEY TECHNOLOGIES AND REQUIREMENTS(2) Satellite and FSO communications① Satellite quantum key distribution (QKD) technology【 Outline of technology 】

・This technology provides an information-theoretic secure method to share cryptographic keys
through quantum communication between the ground and a satellite, or between satellites. (See“Secure backbone network with satellite QKD” on p. 21.)

QUANTUM NETWORKEVOLUTION【 What kind of system? Why do we need it? 】

・ In terrestrial QKD networks, the optical loss of optical fibers sets a limit on the transmission
distance of QKD. So a huge number of QKD devices and trusted nodes are required for globalization.
On the other hand, the thickness of the atmosphere surrounding the earth is about 10 km, and theoptical loss in space is very small. Therefore, satellite-to-ground communication can greatly increase
the transmission distance of QKD. Satellite QKD is an essential technology for the globalization of
QKD networks.

Chap.4
KEY TECHNOLOGIESAND REQUIREMENTS【 International trends 】

・ NICT has demonstrated quantum communication between a 50-kg small satellite and a groundstation, which is the basis of the QKD.4 Meanwhile, China has successfully conducted a QKD
experiment 5 between a low-earth orbit satellite and the ground. Research on satellite QKD isaccelerating among governments, universities, and venture companies around the world.

【 Requirements 】
Chap.5・ In addition to the development of a new QKD protocol optimized for satellite communications, it

R&D ROADMAP

will be necessary to develop pointing acquisition and tracking technology as well as adaptive optics
technology to stabilize the satellite-to-ground link. Moreover, high-speed and high-sensitivity singlephoton detector technology to detect photons is required.
② Physical layer encryption

Chap.6・ Unlike QKD, which is secure against any physically possible attack, physical-layer cryptography
provides an information-theoretically secure method for key establishment under the restrictions
on eavesdropper's attack models, such as when eavesdroppers eavesdrop from the outside of theline-of-sight between the sender and receiver. (See “Secure backbone network with satellite QKD”
on p. 21, “Local secure network with QKD and physical layer encryption” on p. 22, and “New security
infrastructure with post-quantum cryptography infrastructure” on p. 23.)

【 What kind of system? Why do we need it? 】

CONCLUSION

・This technology is used as a complementary technology to QKD in communication systems such as
satellite-to-ground and mobile communications, where the current QKD does not provide sufficientperformance or is difficult to implement.

4. H. Takenaka, et al., Nat. Photonics (2017)
5. S.–K. Liao, et al., Nature (2017)

Chap.4 KEY TECHNOLOGIES AND REQUIREMENTSPROMOTION STRATEGY
Chap.7【 Outline of technology 】

29

Chap.1
INTRODUCTION

04

CHAPTER.4
KEY TECHNOLOGIES AND REQUIREMENTS

・ NICT is conducting a series of researches on physical-layer cryptography in free-space optical

IMAGE AND USE CASES OF
QUANTUM NETWORKS IN SOCIETY【 International trends 】
Chap.2

communications.6 Companies and universities dealing with QKD have applied for patents on similar

Chap.3concepts.7【 Requirements 】

・In order to apply physical-layer cryptography to satellite-to-ground communication, it is necessary
to develop protocols, technologies for establishing links such as pointing, acquisition and tracking
systems, and high-speed and high-sensitivity single-photon detector technologies similar tosatellite QKD technology. On the other hand, in order to apply physical-layer cryptography to mobile

QUANTUM NETWORKEVOLUTION

communications, it is necessary to develop protocols suitable for high-frequency bands (millimeterwaves, terahertz waves, and LEDs).
③ Satellite-terrestrial network coordination technology (adaptive routing technology)【 Outline of technology 】

Chap.4・ This technology is used for continuously providing secure communication services by selecting

KEY TECHNOLOGIESAND REQUIREMENTS

the optimum route and transmission protocol (QKD/physical-layer encryption, etc.) for the entire
satellite/terrestrial network, taking into consideration user requirements such as the required levelof security and natural conditions such as the weather. (See “Secure backbone network with satellite
QKD” on p. 21.)
【 What kind of system? Why do we need it? 】

・ For example, when satellite QKD/physical-layer cryptography cannot be provided due to cloudy

Chap.5weather, it is necessary to select a ground station in a sunny area. In order to provide secure service

R&D ROADMAP

without fatal delay, the terrestrial network route must also be appropriately changed according tothis ground station selection.
【 International trends 】

・ The change of ground stations based on weather conditions in satellite optical communications iscalled site diversity. NICT has been conducting R&D on this technology.8

Chap.6【 Requirements 】

information and share it with satellite nodes and ground nodes. In addition, technologies are
required to enable the miniaturization, portability, and installation of ground stations on ships inorder to establish links with satellites at various locations on the ground.

Chap.7
CONCLUSION

6. H. Endo, et al., Opt. Express (2018); H. Endo, et al., OSA Continuum (2020)
7. M. Legre and B. Huttner, EP 3337063 A1 (2016); E. J. A. Ling, et al., WO 2019/139544 A1 (2019); M. Legre and B. Huttner, EP 3337063 A1 (2016); E. J. A. Ling, et al., WO 2019/139544 A1 (2019)
8. K. Suzuki, ICSO2014, or OBSOC

Chap.4 KEY TECHNOLOGIES AND REQUIREMENTSPROMOTION STRATEGY・ Technologies are required to collect information on communication channels such as weather

30

Chap.1
INTRODUCTION
Chap.2IMAGE AND USE CASES OF
QUANTUM NETWORKS IN SOCIETY
Chap.304

CHAPTER.4
KEY TECHNOLOGIES AND REQUIREMENTS(3) Quantum network① Quantum interface【 Outline of technology 】

・ This technology is used to transmit quantum information between different quantum physicalsystems without changing the quantum information. It is also called quantum media conversion.

【 What kind of system? Why do we need it? 】

QUANTUM NETWORKEVOLUTION

・ It is needed to realize quantum connections via photons between quantum systems of matter that
constitute spatially separated nodes.

【 International trends 】

・ It has been reported that a fluorescent photon was generated from a quantum system of matterand converted into a communication wavelength band photon.9,10It has also been reported that aquantum connection between two spatially separated quantum systems of matter was formed via

Chap.4photons.11

KEY TECHNOLOGIESAND REQUIREMENTS【 Requirements 】

・A technique for manipulating quantum entanglement is required to generate quantum correlations
between the quantum system of matter and the emitted photons. High-performance photon
detectors are needed to measure the interference between the two photons generated at the senderand receiver with high efficiency. A quantum memory is needed to hold the quantum state until thephotons propagate, and the measurement of interference and the manipulation into a quantum

Chap.5system of matter are performed.

R&D ROADMAP
Chap.6② Quantum repeater【 Outline of technology 】

・ This technology enables quantum information to be transmitted over long distances by placing
multiple quantum-connected nodes at relay points.

CONCLUSION【 What kind of system? Why do we need it? 】

・ In principle, quantum states cannot be replicated, so signal attenuation due to loss in thecommunication channel cannot be recovered by amplification. Therefore, quantum repeaters are

9. Phys. Rev. Lett. 120, 203601 (2018)
10. Nat. Comm. 9, 1998 (2018). npj Quant. Inf. 5, 72 (2019)11. Phys. Rev. Lett. 119, 010402 (2017), Nature 578, 240 (2020). Nature 526, 682 (2015)

Chap.4 KEY TECHNOLOGIES AND REQUIREMENTSPROMOTION STRATEGY
Chap.7

Figure 21 : Role of the quantum interface

31

Chap.1
INTRODUCTION

04

CHAPTER.4
KEY TECHNOLOGIES AND REQUIREMENTS

necessary to extend the distance of quantum connections. It can also be used to extend the distance
Chap.2IMAGE AND USE CASES OF
QUANTUM NETWORKS IN SOCIETY
Chap.3of QKD.
【 International trends 】

・ In Japan and overseas, research and development of standard methods consisting of quantum
entanglement swapping, quantum entanglement purification, and quantum memory is underway. Improving the performance of quantum memory is considered to be the key to realization.12In
addition, an all-optical quantum repeater protocol that does not use quantum memory has been
proposed in Japan,13and demonstration experiments are under way. 14

QUANTUM NETWORKEVOLUTION【 Requirements 】

・ In addition to techniques for controlling quantum entanglement such as quantum entanglement
swapping and quantum entanglement purification, a quantum memory is required to maintain thequantum state until the end of the series of operations. In the all-optical quantum repeater protocol,
quantum memory is not required. High-performance photon detectors are required to observe
photon interference in quantum entanglement operations with high efficiency.

Chap.4
KEY TECHNOLOGIESAND REQUIREMENTS
Chap.5
R&D ROADMAP

Figure 22 : Mechanism of quantum repeaters③ Multi-kind quantum network control and management

Chap.6・ This technology enables the stable and inexpensive provision of a wide variety of virtual quantum
networks (including quantum computer virtualization) that satisfy the requirements of various futureapplications, including QKD networks, on the same physical network.

【 What kind of system? Why do we need it? 】

・ It is necessary to satisfy various application requirements (cryptographic key size in QKD,
communication performance, stability of quantum applications, etc.) while curbing costs by reducing

CONCLUSION

physical devices managed by network operators.

12. Nature Photonics 10, 381 (2016)
13. Nature Communications 6, p. 6787 (2015)
14. Nature Communications 10, 378 (2019); Nature Photonics 13, 644 (2019)

Chap.4 KEY TECHNOLOGIES AND REQUIREMENTSPROMOTION STRATEGY
Chap.7【 Outline of technology 】

32

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INTRODUCTION

04

CHAPTER.4
KEY TECHNOLOGIES AND REQUIREMENTS

・ The ITU-T SG13 is currently discussing software-defined network control (SDN control) and

IMAGE AND USE CASES OF
QUANTUM NETWORKS IN SOCIETY【 International trends 】
Chap.2

virtualization for QKD networks,15 while the IRTF is discussing the Quantum Internet (quantum

Chap.3

networks).16In addition, several projects related to quantum networks have already been launched inEurope and the United States. In the United States, for example, the National Quantum Coordination
Office launched by the White House Office of Science and Technology Policy (OSTP) has published areport on the National Strategy of Quantum Information Science.16 In Europe, the Delft University ofTechnology in the Netherlands has published a report on future quantum networks, including the
Quantum Internet.17

QUANTUM NETWORKEVOLUTION【 Requirements 】

・ In order to construct virtual quantum networks that satisfy the requirements of various
applications, and to respond to changes in conditions such as network traffic fluctuations and fault
detection, it is important to achieve agility and effectiveness in route selection, rerouting, resource
allocation, and so on. This will enable the networks to enhance the stability of applications.
・ Moreover, applying policy control (e.g.: SDN) and in-network computing technologies (e.g.:

Chap.4

information-centric networking and network coding18 ), which have been actively researched and

KEY TECHNOLOGIESAND REQUIREMENTS

developed in classical networks, is expected to be effective.
・ In addition, advanced security technologies will be needed to ensure the safety and security ofcontrol and management mechanisms, as well as the integration of terrestrial and satellite-based
network technologies to realize global virtual quantum networks in the future.

Chap.5
R&D ROADMAP
Chap.6④ Quantum sensor network (e.g.: quantum network of optical clocks)

CONCLUSION【 Outline of technology 】

・ Devices that use quantum effects to measure physical quantities are called quantum sensors.
Atomic clocks that use optical frequencies are called optical clocks, and they are also used as

15. ITU-T SG13 Y.QKDN-SDNC (June 2020)
16. ITRF QIRG-ID: “Applications and Use Cases for the Quantum Internet”(draft-irtf-qirg-quantum-internet-use-cases-04) (January 2021)
16. “Quantum Frontiers: Report on Community Input to the Nation’s Strategy for Quantum Information Science,” The White House National Quantum Coordination Office (October 2020)
17. “Creating the Quantum Future – QuTech Annual Report 2019,” Delft Univ. of Tech. (March 2019)18. K. Matsuzono, et al., “Low Latency Low Loss Streaming using In-Network Coding and Caching,” Proc. IEEE Infocom (May 2017)

Chap.4 KEY TECHNOLOGIES AND REQUIREMENTSPROMOTION STRATEGY
Chap.7

Figure 23 : Mechanism of quantum networks

33

Chap.1
INTRODUCTION

04

CHAPTER.4
KEY TECHNOLOGIES AND REQUIREMENTS

quantum sensors to measure gravity. Coherent links that connect optical clocks with optical fibers
Chap.2or free space enable the distribution of space-time information and gravity crowdsensing without

IMAGE AND USE CASES OF
QUANTUM NETWORKS IN SOCIETY

deploying quantum network technology. In a quantum network of optical clocks, an extension of theChap.3link supported by quantum connections, the measurement speed can be reduced to the limit allowedby physical laws.
【 What kind of system? Why do we need it? 】

・ The technology is essential for the realization of high-precision timing distribution for nextgeneration communications, phase synchronization for coherent optical communications, and ultralong baseline interferometry. As a gravity sensor, it may be effective for monitoring underground

QUANTUM NETWORKEVOLUTION

cavities, magma reservoirs, and seafloor fluctuations.
【 International trends 】

・ Construction of a coherent link with a total length of more than 2,000 km is in progress in Europe.19
In Japan, RIKEN, the University of Tokyo, NICT, and other organizations are conducting R&D on acoherent link. A link with a total length of 240 km has been reported.20 To date, the quantum network

Chap.4of optical clocks has merely been proposed; there has been no report on actual implementation.21

KEY TECHNOLOGIESAND REQUIREMENTS【 Requirements 】

・ A coherent link that faithfully transmits the frequency accuracy of the optical clock is required. To
plug in quantum connectivity, a quantum interface between atoms or ions and photons is required.
When the fiber length between optical clocks exceeds 100 km, quantum repeaters are required.

Chap.5
R&D ROADMAP
Chap.6⑤ Quantum computing (ion-trap quantum computer)【 Outline of technology 】

・An ion-trap quantum computer consists of atomic ions laser-cooled in an ion trap as qubits. All thequbits are connected via the phonons of the oscillating motion caused by the trap electric field as a

CONCLUSION

quantum bus. An ion-trap quantum computer with a quantum interface between ions and photons iscalled an optically connected ion-trap quantum computer.

19. https://www.clonets.eu/clonets-consortium.html
20. Optics Express 28, 9186 (2020)
21. Nature Physics 10, 583 (2014)

Chap.4 KEY TECHNOLOGIES AND REQUIREMENTSPROMOTION STRATEGY
Chap.7

Figure 24 : Quantum network of optical clocks

34Chap.1
INTRODUCTION

04

CHAPTER.4
KEY TECHNOLOGIES AND REQUIREMENTS

・An ion-trap quantum computer with a single ion trap is considered to be limited to about 50 qubits

IMAGE AND USE CASES OF
QUANTUM NETWORKS IN SOCIETY【 What kind of system? Why do we need it? 】
Chap.2due to fundamental and technical limitations. Large-scale quantum computation is expected to be

Chap.3

possible by connecting multiple ion-trap quantum computers via photons.
【 International trends 】

・ In the United States and Europe, ion-trap quantum computers with up to 32 qubits without opticalconnectivity have been realized, and cloud quantum computing services have been launched.22An
ion-trap quantum computer with optical connectivity has not yet been realized, and research anddevelopment are under way in the United States and Europe with the goal of achieving 50 qubits.23

QUANTUM NETWORKEVOLUTION

In Japan, research and development has begun under the Moonshot Research and Development
program.24【 Requirements 】

・ A highly functional ion trap with a quantum interface with photons that can perform quantum
computation with about 10 qubits is needed. Quantum wavelength conversion technology is required

Chap.4to convert the wavelength of the photons generated by the ion trap into the optical communication

KEY TECHNOLOGIESAND REQUIREMENTS

wavelength for connecting to an optical switch. Two-photon interference technology and highperformance photon detectors are required to perform optical connection operations.

Chap.5
R&D ROADMAP

Figure 25 : Optically connected ion-trap quantum computer

Chap.6【 Outline of technology 】

・Superconducting electric circuits cooled to cryogenic temperatures behave quantum mechanically,
and are called superconducting quantum circuits. Superconducting quantum circuits have a highdegree of freedom in their design, and can be made into qubits, resonant circuits, waveguides,
coupled circuits, and so on. A superconducting quantum computer is a system consisting of a large
number of qubits capable of qubit gate operation and state measurement.

CONCLUSION【 What kind of system? Why do we need it? 】

・ Quantum computers are much more powerful than present computers at solving certain classes
of problems by deploying quantum mechanical resources to computation. Superconducting quantum

22. https://ionq.com/, https://www.aqt.eu/
23. https://www.aqtion.eu/
24. https://www.jst.go.jp/moonshot/en/program/goal6/

Chap.4 KEY TECHNOLOGIES AND REQUIREMENTSPROMOTION STRATEGY
Chap.7⑥ Quantum computing (superconducting quantum computer)

35

Chap.1
INTRODUCTION

04

CHAPTER.4
KEY TECHNOLOGIES AND REQUIREMENTS

computers are considered to be one of the most promising candidates for quantum computers
Chap.2IMAGE AND USE CASES OF
QUANTUM NETWORKS IN SOCIETY
Chap.3

because of their high degree of freedom in design and integration.
【 International trends 】

・ In 2019, Google demonstrated quantum supremacy in a sample containing 53 qubits.25
Thus, research and development of NISQ (noisy intermediate-scale quantum computers) 26, asuperconducting quantum computer consisting of several tens of qubits without error correction, is
actively being conducted. In Japan, the Q-LEAP Flagship project 27and the Moonshot Research andDevelopment program 28 are conducting research and development.

QUANTUM NETWORKEVOLUTION【 Requirements 】

・Research and development of qubits with long coherence time is necessary. In addition, microwave
transmission technology with low reflection and loss, high-precision microwave pulse generation
technology, high-sensitivity microwave measurement technology, and high-speed signal processing
technology are required for high-speed and high-precision qubit gate operation, qubit measurement,
and quantum feedback. Furthermore, it is necessary to increase the cooling power of dilution

Chap.4

refrigerators and to improve the reproducibility of superconducting quantum circuit fabrication

KEY TECHNOLOGIESAND REQUIREMENTS

technology.

Chap.5
R&D ROADMAP

Figure 26 : Superconducting quantum computer

Chap.6

CONCLUSION

25. https://www.nature.com/articles/s41586-019-1666-5
26. https://doi.org/10.22331/q-2018-08-06-79
27. https://www.jst.go.jp/stpp/q-leap/en/index.html
28. https://www.jst.go.jp/moonshot/en/program/goal6/

Chap.4 KEY TECHNOLOGIES AND REQUIREMENTSPROMOTION STRATEGY
Chap.736

Chap.1
INTRODUCTION

05

CHAPTER.5
R&D ROADMAP・ For the key technologies in Chapter 4, we have compiled a roadmap for the period from 2020 to 2035.
Chap.2

The roadmap for research and development of terrestrial and satellite quantum key distribution (QKD)

IMAGE AND USE CASES OF
QUANTUM NETWORKS IN SOCIETY

networks is as follows.

Chap.3
QUANTUM NETWORKEVOLUTION
Chap.4
KEY TECHNOLOGIESAND REQUIREMENTS
Chap.5Figure 27 : R&D Roadmap for QKD networks

R&D ROADMAP
Chap.6PROMOTION STRATEGYCONCLUSION

Chap.5 R&D ROADMAP

Chap.737

Chap.1
INTRODUCTION

05

CHAPTER.5
R&D ROADMAP・The roadmap for research and development of quantum networks is as follows.
Chap.2IMAGE AND USE CASES OF
QUANTUM NETWORKS IN SOCIETY
Chap.3
QUANTUM NETWORKEVOLUTION
Chap.4
KEY TECHNOLOGIESAND REQUIREMENTS

Figure 28 : R&D Roadmap for quantum networks

Chap.5
R&D ROADMAP
Chap.6PROMOTION STRATEGYCONCLUSION

Chap.5 R&D ROADMAP

Chap.738

Chap.1
INTRODUCTION
Chap.206

CHAPTER.6
PROMOTION STRATEGY

1. Overview of quantum network technology

IMAGE AND USE CASES OF
QUANTUM NETWORKS IN SOCIETY・ A promotion strategy will be necessary for NICT to develop QKD networks and quantum networks insociety in cooperation with external stakeholders.
・In order to deploy quantum networks in society, it is necessary to promote five initiatives in an integrated
manner: (1) research and development, (2) social implementation, (3) international collaboration, (4)system design, and (5) human resource development.

Chap.3
QUANTUM NETWORKEVOLUTION
Chap.4
KEY TECHNOLOGIESAND REQUIREMENTS
Chap.5
R&D ROADMAP

Figure 29 : Promotion strategy for the development of quantum networks in society (overview)

2. Individual Promotion Strategies(1) Research and development

Chap.6

・ Based on national plans and strategies as well as NICT’s Fifth Medium-to-Long-Term Plan, NICT willconduct research and development of quantum network technologies and secure related patents. In fields
where it will take five to ten years to achieve research results, we will promote the significance of theresearch and its results to obtain continuous investment.

【 Promoting technology transfer of research results at NICT 】

・ NICT will promote research and development for companies to catch up with the technology in

CONCLUSION

cooperation with the government and other organizations. The system for transferring technologies andbasic research results at NICT also needs to be improved.

Chap.6 PROMOTION STRATEGYPROMOTION STRATEGY
Chap.7【 Promoting continuous R&D at NICT 】

39

Chap.1
INTRODUCTION

06

CHAPTER.6
PROMOTION STRATEGY・ In technology fields where the market size is unclear and it is difficult for companies to participate,

IMAGE AND USE CASES OF
QUANTUM NETWORKS IN SOCIETY【 Promoting R&D through national projects 】
Chap.2such as quantum network technology for which R&D is being conducted mainly in Europe and theChap.3
QUANTUM NETWORKEVOLUTION
Chap.4

United States, it is necessary to promote R&D by establishing a system for collaboration among industry,
academia, and government through national projects.

(2) Social implementation【 Establishing a testbed 】

・ NICT will establish an open testbed that connects quantum technology innovation hubs in cooperation
with the government, companies, etc., and will upgrade the Tokyo QKD Testbed. (See “Initiatives forbuilding quantum technology platforms” on p. 61.)・ Through the testbed, NICT will combine the achievements of national projects led by governments toconsolidate and effectively utilize resources in Japan, and establish a framework for joint use amongindustry, academia, and government.

【 Providing application development infrastructure (establishing the business ecosystem) 】

KEY TECHNOLOGIESAND REQUIREMENTS

・ NICT will collaborate with governments, companies, the Quantum ICT Forum, and others to provide
opportunities to examine and demonstrate new services and use cases at various layers, strengthen
application development, and examine business ecosystem models.

【 Fostering industry 】

・ NICT will accelerate the diffusion and deployment of quantum networks by promoting R&D and social
implementation of quantum networks by telecommunications carriers and service providers.

Chap.5・ To be able to manufacture major devices and parts for quantum networks in Japan, NICT will actively

R&D ROADMAP

collaborate with related companies such as vendors and component manufacturers in Japan, support thecreation of parts manufacturing and business models, and promote the establishment of supply chains.
We will also consider the creation of start-up companies by NICT.

(3) International cooperation
Chap.6・ Considering international R&D trends on various quantum technologies, such as ion traps andsuperconductivity, NICT will collaborate with domestic and oversea research institutes and will also
consider applications of the research achievements on quantum communications.
・Toward the realization of quantum networks, NICT will promote collaboration with other universities andresearch institutions in order to strengthen R&D of quantum repeater technology, network architecture,
software, etc.

【 Forming research communities 】

CONCLUSION

・ NICT will promote the acquisition of research funds by participating in national projects such as theMoonshot Research and Development Program and Q-LEAP, and will also promote the formation ofresearch communities involving participants of national projects and researchers from universities andresearch institutions.

Chap.6 PROMOTION STRATEGYPROMOTION STRATEGY
Chap.7【 Collaborating with universities and research institutions 】

40

Chap.1
INTRODUCTION

06

CHAPTER.6
PROMOTION STRATEGY【 Forming and supporting consortiums 】
Chap.2IMAGE AND USE CASES OF
QUANTUM NETWORKS IN SOCIETY
Chap.3

・NICT will promote collaboration among companies and universities through the Quantum ICT Forum.

・ A consortium of quantum technology and Internet researchers from industry, academia, and publicresearch institutes has been formed to promote quantum networks, and NICT will participate in andsupport such interdisciplinary communities.
【 Organizing a global partner network 】

・ NICT will accelerate the R&D of quantum networks while taking into account the fact that quantum
technology is closely related to international competition and national security. NICT will also actively
promote the network of global strategic partners and standardization proponents in order to build an

QUANTUM NETWORKEVOLUTION

international testbed.
【 Launching collaboration programs with foreign institutions 】

・ NICT will promote discussions on the direction of future R&D and international collaboration, utilizing
the framework of collaboration with the EU and NSF. NICT will strive to make Japanese technology
available worldwide, even though the human and financial resources for R&D on quantum technology are

Chap.4limited.

KEY TECHNOLOGIESAND REQUIREMENTS(4) System design【 Promoting international standardization 】

・ NICT, in cooperation with governments and companies, will promote international standardization at
the International Telecommunication Union Telecommunication Standardization Sector (ITU-T) and theInternational Organization for Standardization/International Electrotechnical Commission (ISO/IEC JTC1),

Chap.5for the global spread of quantum network technologies (especially QKD network technologies).

R&D ROADMAP【 Developing an evaluation and certification framework 】

・ NICT, in cooperation with the government, companies, the Quantum ICT Forum, etc., will promote thedevelopment of appropriate methods for assessing the security of QKD devices, the documentation of
security requirements (so-called Protection Profiles (PPs)) in compliance with international standards
developed by ISO/IEC, etc., and the development of an operation framework for PPs.

Chap.6・ NICT, in cooperation with companies, etc., will consider the application of insurance and reduction ofpremiums for the introduction of QKD.

(5) Human resource development【 Developing and securing quantum natives 】

・NICT will develop “quantum natives” through the NICT Quantum Camp (NQC) program, which started in

CONCLUSION

2020, in collaboration with governments, universities, companies, etc. NICT will also consider developing
human resources with broad knowledge including quantum algorithms, high-level programming
languages, architecture, etc., as well as human resources who can design the entire system.

Chap.6 PROMOTION STRATEGYPROMOTION STRATEGY
Chap.7【 Application to cyber insurance 】

41

Chap.1
INTRODUCTION

06

CHAPTER.6
PROMOTION STRATEGY・ NICT will continue to secure human resources for research by accepting student and adult interns at
Chap.2IMAGE AND USE CASES OF
QUANTUM NETWORKS IN SOCIETY
Chap.3

NICT, expanding collaboration with universities, and developing attractive career paths.
【 Developing and securing diverse quantum human resources 】

・ NICT will secure human resources with various skills not only in research but also in technology,
intellectual property management, accounting, etc., in order to strengthen NICT as a researchorganization.

【 Utilizing NICT’s Quantum Security Hub 】

QUANTUM NETWORKEVOLUTION

・ NICT will conduct human resource development and hold seminars utilizing the co-creation space at
NICT’s new building as the Quantum Security Hub. NICT will also promote practical human resource
development programs utilizing the open testbed by connecting various quantum research hubs.

Chap.4
KEY TECHNOLOGIESAND REQUIREMENTS
Chap.5
R&D ROADMAP
Chap.6

CONCLUSION

Chap.6 PROMOTION STRATEGYPROMOTION STRATEGY
Chap.7

Figure 30 : Initiatives for building quantum technology platforms

42Chap.1
INTRODUCTION

07

CHAPTER.7
CONCLUSION

・This White Paper summarizes the image of society, use cases, key technologies, the R&D roadmap from
Chap.22021 to 2035, and the promotion strategy for quantum network ｓ .

IMAGE AND USE CASES OF
QUANTUM NETWORKS IN SOCIETY・ With regard to quantum networks, work on the social implementation of QKD and research anddevelopment for the Quantum Internet are under way internationally. In the future, in accordance with theFifth Medium-to-Long-Term Plan of NICT and based on the promotion strategy of this White Paper, NICT
will collaborate with experts, companies, universities, and research institutions in Japan and overseas topromote the use of quantum networks in society.

・NICT will update this White Paper based on future international trends and the latest R&D.

Chap.3
QUANTUM NETWORKEVOLUTION
Chap.4
KEY TECHNOLOGIESAND REQUIREMENTS
Chap.5
R&D ROADMAP【 Authors at NICT 】
ASAEDA Hitoshi, ENDO Hiroyuki, FURUSAWA Kentaro, HACHISU Hidekazu, HAYASAKA Kazuhiro,
Chap.6PROMOTION STRATEGY

Kazuhisa, MIKI Shigeto, MIYAZAWA Takaya, MOROHASHI Isao, NEMITZ Nils, OTSUBO Nozomu, SAITO
Yoshihiko, SASAKI Akihiko, SASAKI Masahide, SEKINE Norihiko, SEMBA Kouichi, SHONO Shiho,
TAKEOKA Masahiro, TERAI Hirotaka, TOYOSHIMA Morio, TSUJIMOTO Yoshiro, YAMAGUCHI Yuya,
YANAGISAWA Kotaro, YOSHIHARA Fumiki【 Update History 】- Release 0.9: April 30, 2021

CONCLUSIONThe English text (version 0.9) was translated from the Japanese text (version 1.0) by White Paper staff
using TexTra*, a machine translation system developed by NICT.
https://mt-auto-minhon-mlt.ucri.jgn-x.jp/

Chap.7 CONCLUSION

Chap.7

IDE Shinji, IDO Tetsuya, IHARA Toshiyuki, ISHITANI Yasuki, IZUMI Akie, KANNO Atsushi, MATSUZONO

43

Quantum Network White Paper
Published August 2021
ISBN:978-4-904020-21-0

National Institute of Information and Communications Technology
4-2-1 Nukuikitamachi, Koganei City, Tokyo 184-8795, JAPANE-mailURL

nict-idi-wp@ml.nict.go.jp
https://www2.nict.go.jp/idi/en/

Unauthorized copying and replication of the contents of this paper are prohibited.