Liaison statement
LS on work progress on Quantum Key Distribution (QKD) network in SG13 (as of November 2023)

ITU-T SG13 is pleased to inform you of our progress on Quantum Key Distribution
(QKD) topics. By October 2023 SG13 published 19 Recommendations and 3
Supplements on QKDN as follows:

- Recommendation ITU-T Y.3800 “Overview on networks supporting quantum key
distribution”; - Recommendation ITU-T Y.3801 “Functional requirements for
quantum key distribution networks”; - Recommendation ITU-T Y.3802 “Quantum key
distribution networks – Functional architecture”; - Recommendation ITU-T Y.3803
“Quantum key distribution networks – Key management”; - Recommendation ITU-T
Y.3804 “Quantum key distribution networks - Control and management”; -
Recommendation ITU-T Y.3805 “Quantum Key Distribution Networks - Software
Defined Networking Control”; - Recommendation ITU-T Y.3806 “Quantum key
distribution networks - Requirements for quality of service assurance”; -
Recommendation ITU-T Y.3807 “Quantum Key Distribution networks - QoS
parameters”; - Recommendation ITU-T Y.3808 “Framework for integration of
quantum key distribution network and secure storage network”; - Recommendation
ITU-T Y.3809 “A role-based model in quantum key distribution networks
deployment”; - Recommendation ITU-T Y.3810 “Quantum key distribution network
interworking - Framework”; - Recommendation ITU-T Y.3811 “Quantum key
distribution networks - Functional architecture for quality of service
assurance”; - Recommendation ITU-T Y.3812 “Quantum key distribution networks -
Requirements for machine learning based quality of service assurance”; -
Recommendation ITU-T Y.3813 “Quantum key distribution networks interworking –
functional requirements”; - Recommendation ITU-T Y.3814 “Quantum key
distribution networks - functional requirements and architecture for machine
learning enablement”; - Recommendation ITU-T Y.3815 “Quantum key distribution
networks - overview of resilience”; - Recommendation ITU-T Y.3816 “Quantum key
distribution networks - Functional architecture enhancement of machine learning
based quality of service assurance”; - Recommendation ITU-T Y.3817 “Quantum key
distribution networks interworking - Requirements of quality of service
assurance”; - Recommendation ITU-T Y.3818 “Quantum key distribution networks
interworking – architecture”; - Supplement ITU-T Y.Sup70 to Y.3800-series
“Quantum Key Distribution Networks - Applications of Machine Learning”; -
Supplement ITU-T Y.Sup74 to Y.3800-series “Standardization roadmap on Quantum
Key Distribution Networks”; - Supplement ITU-T Y.Sup75 to Y.3000-series
“Quantum key distribution networks - Quantum-Enabled Future Networks”.

1.The item consented at the November 2023 SG13 meeting
The draft Recommendation ITU-T Y.3819 (ex Y.QKDN-amc) was consented at SG13
meeting (Geneva, 23 October – 3 November 2023).

Draft Recommendation ITU-T Y.3819 (ex Y.QKDN-amc) “Quantum key distribution
networks - requirements and architectural model for autonomic management and
control” in TD165/PLEN

This Recommendation specifies one possible set of functional requirements and a
possible architectural model for autonomic management and control (AMC) in
QKDNs.

2. The items agreed at the November 2023 SG13 meeting
The Technical Report (ex TR.QN-UC), Supplement 80 to ITU-T Y.3800-series (ex
Y.supp.QKDN-UC), Supplement 79 to ITU-T Y.3800-series (formerly TR.QKDN-nq)
were agreed.

Technical Report ITU-T TR.QN-UC “Use cases of quantum networks beyond QKDN” in
TD182/PLEN This Technical Report analyses use cases of quantum networks beyond
quantum key distribution network (QKDN) in the context of networking
technologies as the mandate of ITU-T SG13.

The uses cases which are only applied by quantum networks beyond QKDN are
collected, investigated and summarized; all use cases are analysed by problem
statement, technical considerations along with a short description of each use
case. This Technical Report also provides analyses for future applications and
potential standardization considerations.

Supplement 80 to ITU-T Y.3800-series (ex Y.supp.QKDN-UC) “Use cases of quantum
key distribution networks” in TD179/PLEN

This Supplement consolidates the QKDN use cases in the context of networking
technologies as the mandate of ITU-T SG13.

Through a comprehensive analysis, the QKDN uses cases are classified into
several classes and this Supplement highlights the competitive advantage of the
use cases brought by QKDN and provides suggestions for future standardization
efforts in ITU-T SG13.

Supplement 79 to ITU-T Y.3800 series (formerly TR.QKDN-nq) “Quantum key
distribution networks – Role in end-to-end cryptographic services with
non-quantum cryptography” in TD178/PLEN

Based on [ITU-T Y.3800], many study items are successfully developed and
developing so far. However, in case when mobile objects (i.e., autonomous car,
mobile phone, etc.) are to be supplied by quantum key distribution (QKD)
service, there is a difficulty to establish and maintain a quantum channel
stably with them. Key supply agent-keys (KSA-keys) are not able to be supported
in this situation.

For the purpose of delivery of KSA-keys generated from quantum key distribution
network (QKDN) into the mobile objects, the keys can be delivered through user
network using modern cryptography technology (especially key exchange protocol).

Therefore, the integration of QKDN with non-quantum cryptography will enable
the QKD network and service providers, bringing its cryptography service to a
much wider range of business opportunity.

For this purpose, the relationship between QKDN and end-to-end (E2E)
cryptography service will be introduced. Then, relative use cases for the
integration of QKDN with non-quantum cryptography will be described. Finally,
based on the analysis of the detailed attributes of use cases, implications in
terms of further study issue will be identified.

3. Revised on-going work items after July 2023 SG13 activities

Draft Recommendation ITU-T Y.QKDNi_SDNC “Quantum Key Distribution Network
Interworking – Software Defined Networking Control” in TD400/WP3

This draft Recommendation specifies the Software Defined Network control for
the interworking including the overview of the role of SDN control for the
interworking between QKDN providers, the functional entities of SDN control for
the interworking, the interfaces of SDN control for the interworking, the
functional requirements of SDN control for the interworking, and the security
considerations.

Draft Recommendation ITU-T Y.QKDNf_fr “Framework of Quantum Key Distribution
Network Federation” in TD401/WP3

This draft Recommendation specifies the framework of Quantum Key Distribution
Network Federation (QKDNf) including the overview of QKDNf, reference
architecture for enabling QKDNf, functional entities of QKDNf, reference points
for the QKDNf, functional requirements of the QKDNf, overall operational
procedures of QKDNf and security considerations.

Draft Recommendation ITU-T Y.QKDN_SSNreq “Functional requirements for
integration of quantum key distribution network and secure storage network" in
TD402/WP3

This Recommendation specifies functional requirements for integration of
quantum key distribution network and secure storage network. It includes
detailed description of the followings:

- functional requirements for SSN user plane    ;
- functional requirements for SSN control plane;
- functional requirements for SSN storage plane;
- functional requirements for SSN management plane.

Draft Recommendation ITU-T Y.QKDN_SSNarch “Functional architecture for
integration of quantum key distribution network and secure storage network" in
TD403/WP3

This draft Recommendation will study the functional architecture for
integration of quantum key distribution network and secure storage network. It
includes detailed description of the followings:

- functional architecture model;
- functional elements;
- reference points;
- share format and metadata;
- storage configuration;
- operational procedures.

Draft Recommendation ITU-T Y.QKDN-rsrq “Requirements for quantum key
distribution network resilience” in TD404/WP3 For quantum key distribution
networks (QKDN), Recommendation ITU-T Y.QKDN-rsrq specifies the general
requirements for resilience, and separately specifies the supporting
requirements for protection and recovery. Draft Recommendation ITU-T
Y.QKDN-TSNfr “Framework for integration of quantum key distribution network and
time sensitive network " in TD405/WP3

This Recommendation specifies the framework for integration of quantum key
distribution network (QKDN) and time sensitive network (TSN) including the
overview and scenarios of QKDN and TSN integration, the network capabilities to
support QKDN and TSN integration, the conceptual structure and basic functions
of QKDN and TSN integration, and its overall operational procedures and
security considerations.

Draft Supplement ITU-T Y.supp.QKDN_sync “Analysis of Synchronization in Quantum
Key Distribution Networks” in TD406/WP3

This Supplement to ITU-T Y.3800-series Recommendations provides instructive
information on time synchronization solution, function, and implementation in
quantum key distribution networks (QKDN), including time synchronization
function in quantum, key management, network management, and control layers of
QKDN.

4. New work items agreed at the November 2023 SG13 meeting

Draft Recommendation ITU-T Y.QKDN-nq-rf “Quantum key distribution networks –
Requirements and framework for end-to-end QKDN and non-quantum cryptographies
services” in TD411-R1/WP3

In order to support QKD service to IMT-2020 users including mobile objects
(i.e., autonomous car, mobile phone, etc.), it is challenging to establish and
maintain a quantum channel stably with them and supporting KSA-keys. 
TR-QKDN-nq addresses these issues and describes several use cases to deliver
KSA-keys generated from QKD networks to the IMT-2020 user applications by means
of modern cryptography (e.g., PKI technology) with PQC algorithms.  It also
identifies various issues to be addressed for standardization. One of them is
an implication on the end-to-end QoS assurance.

This draft Recommendation specifies use cases, architectural models, high-level
and functional requirements for end-to-end QKDN and non-quantum cryptographies
(NQC) services.

Draft Recommendation ITU-T Y.QKD-TLS “Quantum Key Distribution integration with
Transport Layer Security 1.3” in TD412/WP3

This Draft Recommendation specifies use cases, high-level requirements and
reference models for quantum key distribution (QKD) integration with transport
layer security 1.3 (TLS 1.3).

Draft Recommendation ITU-T Y.QKDN-nq-qos-rf, “Quantum key distribution networks
– Requirements and framework of quality of service assurance for end-to-end
QKDN and non-quantum cryptography services” in TD549/WP1 This draft
Recommendation specifies use cases, architectural models, high-level,
functional requirements, and a framework for quality of service assurance of
end-to-end quantum key distribution network (QKDN) and non-quantum cryptography
(NQC) services.

Draft Recommendation ITU-T Y.QKDNi-qos-fa “Quantum key distribution networks
interworking - Functional architecture for quality of service assurance” in
TD584/WP1

This draft Recommendation specifies the functional architecture of quality of
service (QoS) assurance for the quantum key distribution network interworking
(QKDNi),

Draft Recommendation ITU-T Y.QKDN-da “Quantum Key Distribution Networks –
Dependability Assessment in TD550/WP1 This Recommendation specifies QKDN
dependability assessment conceptual model, indicators, and dependability
assessment process.

Draft Supplement ITU-T Y.supp.TC-QN “Technical considerations towards Quantum
Network” in TD413-R1/WP3 Quantum network is expected to provide new
applications based on fundamental quantum mechanics such as entanglement,
superposition and non-cloning, and those are not possible with non-quantum
networks (e.g. conventional digital networks). This Supplement aims to identify
technical considerations for quantum network.

5. Conclusion

SG13 will study the network aspects of QKD. Q16/13 and Q6/13 look forward to
close cooperation with ITU-T SG2, SG11, SG15, SG17, ETSI ISG-QKD, ISO/IEC
JTC1/SC27, WG14, AG4, IETF/IRTF, and relevant groups for future standardization
on QKD networks.

Attachments:
1) The consented draft Recommendation ITU-T Y.3819 (ex Y.QKDN-AMC) “Quantum key
distribution networks - Requirements and architectural model for autonomic
management and control" (TD165/PLEN); 2) The agreed Technical Report ITU-T
TR-QN-UC “Use cases of quantum networks beyond QKDN” (TD182/PLEN); 3) The
agreed Supplement 80 to ITU-T Y.supp.QKDN-UC “Use cases of quantum key
distribution networks” (TD179/PLEN); 4) The agreed Supplement 79 to ITU-T
Y.3800-series “Quantum key distribution networks – Role in end-to-end
cryptographic services with non-quantum cryptography” (TD178/PLEN); 5) The
updated draft Recommendation ITU-T Y.QKDNi_SDNC “Quantum Key Distribution
Network Interworking – Software Defined Networking Control” (TD400/WP3); 6) The
updated draft Recommendation ITU-T Y.QKDNf_fr “Framework of Quantum Key
Distribution Network Federation” (TD401/WP3); 7) The updated draft
Recommendation ITU-T Y.QKDN_SSNreq “Functional requirements for integration of
quantum key distribution network and secure storage network" (TD402/WP3); 8)
The updated draft Recommendation ITU-T Y.QKDN_SSNarch “Functional architecture
for integration of quantum key distribution network and secure storage network"
(TD403/WP3) 9) The updated draft Recommendation ITU-T Y.QKDN-rsrq “Requirements
for quantum key distribution network resilience” (TD404/WP3); 10) The updated
draft Recommendation ITU-T Y.QKDN-TSNfr “Framework for integration of quantum
key distribution network and time sensitive network” (TD405/WP3); 11) The
updated draft Supplement ITU-T Y.supp.QKDN_sync “Analysis of Synchronization in
Quantum Key Distribution Networks” (TD406/WP3); 12) NWI - Y.QKDN-nq-rf “Quantum
key distribution networks – Requirements and framework for end-to-end QKDN and
non-quantum cryptographies services” in TD411-R1/WP3 13) NWI - Y.QKD-TLS
“Quantum Key Distribution integration with Transport Layer Security 1.3” in
TD412/WP3 14) NWI - Y.QKDN-nq-qos-rf, “Quantum key distribution networks –
Requirements and framework of quality of service assurance for end-to-end QKDN
and non-quantum cryptography services” in TD549/WP1 15) NWI - Y.QKDNi-qos-fa
“Quantum key distribution networks interworking - Functional architecture for
quality of service assurance” in TD584/WP1 16) NWI - Y.QKDN-da “Quantum Key
Distribution Networks – Dependability Assessment in TD550/WP1 17) NWI -
Y.supp.TC-QN “Technical considerations towards Quantum Network” in TD413-R1/WP3