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

ITU-T SG13 is pleased to inform you of our progress on Quantum Key Distribution
(QKD) topics. SG13 has published 15 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”; - Supplement ITU-T Y.Sup70 to Y.3800-series “Quantum Key
Distribution Networks - Applications of Machine Learning”; - Supplement ITU-T
Y.Sup74 to Y.3000-series “Standardization roadmap on Quantum Key Distribution
Networks”; - Supplement ITU-T Y.Sup75 to Y.3800-series “Quantum key
distribution networks - Quantum-Enabled Future Networks”.

1. The items approved after the November 2022 WP3/13 meeting

The draft Recommendations ITU-T Y.3813 and Y.3814 were approved.

Recommendation ITU-T Y.3813 (ex Y.QKDN-iwrq) “Quantum key distribution networks
interworking – functional requirements”

For quantum key distribution networks (QKDN), Recommendation ITU-T Y.QKDN_iwrq
specifies functional requirements for QKDN interworking (QKDNi). This
Recommendation describes the functional requirements for key management layer,
QKDN control layer, and QKDN management layer, for interworking using gateway
nodes (GWNs) and/or interworking nodes (IWNs).

Recommendation ITU-T Y.3814 (ex Y.QKDN-ml-fra) “Quantum key distribution
networks - functional requirements and architecture for machine learning
enablement”

QKDN is expected to maintain stable operations and meet the requirements of
various cryptographic applications efficiently. Due to the advantages of
machine learning (ML) related to autonomous learning, ML can help to overcome
the challenges of QKDN in terms of quantum layer performances, key management
layer performances and QKDN control and management efficiency. Based on the
functional requirements and architecture of QKDN in [ITU-T Y.3801] and [ITU-T
Y.3802], this recommendation is to specify one possible set of functional
requirements and a possible architecture for ML-enabled QKDN (QKDNml),
including the overview, the functional requirements, architecture and
operational procedures of QKDNml.

In the SG13 meeting (Geneva, 13 – 24 March 2023), Q16/13 has made progress of
the following work items.

2. The items agreed at March 2023 SG13 meeting

New Supplement 75 to ITU-T Y.3000-series Recommendation (formerly TR-QEFN),
“Quantum key distribution networks – Quantum-Enabled Future Networks” in
TD96/PLEN

The scope of this Supplement is to describe ITU-T’s Views for Quantum-Enabled
Future Networks (QEFN) for the future networks study to act as a document to
help SG13 to study the future network evolution towards Quantum era.

New Supplement 74 to ITU-T Y.3000-series Recommendation (formerly
Y.supp.QKDN-roadmap), “Standardization roadmap on Quantum Key Distribution
Networks” in TD100/PLEN Supplement Y.supp.QKDN-roadmap to ITU-T Y-series
Recommendations provides the standardization roadmap on quantum key
distribution networks. It describes the landscape with related technical areas
of trust technologies from an ITU-T perspective and list up related standards
and publications developed in standards development organizations (SDOs).

3. Revised on-going work items

Draft Recommendation ITU-T Y.QKDN-rsfr “Quantum key distribution networks –
overview of resilience” in TD222/WP3

For quantum key distribution network (QKDN), this recommendation describes an
overview of QKDN resilience with models of QKDN protection and recovery.

Draft Recommendation ITU-T Y.QKDN-iwac “Quantum key distribution network
interworking - architecture” in TD232/WP3

For quantum key distribution networks (QKDN), Recommendation ITU-T Y.QKDN_iwac
specifies functional architecture for QKDNi.

Draft Recommendation ITU-T Y.QKDNi_SDNC “Quantum Key Distribution Network
Interworking – Software Defined Networking Control” in TD233/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 TD234/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-AMC “Quantum key distribution networks -
Requirements and architectural model for autonomic management and control" in
TD235/WP3

Autonomic Management and Control (AMC) is about Decision-making-Elements (DEs)
as autonomic functions (i.e. control-loops) with cognition introduced in the
management layer as well as in the control layer. Cognition in DEs, enhances DE
logic and enables DEs to manage and handle even the unforeseen situations and
events detected in the environment around the DE(s). As the number and
diversity of devices that make up the individual QKDNs continue to grow,
automating QKDN control and management tasks becomes ever-more important to
improve the quality of services (QoS).

To cope with the challenges of QKDN control and management, while minimizing
human intervention towards full automation of QKDN, this draft Recommendation
specifies the requirements and architectural models for AMC in QKDNs including
the overview, requirements, consideration for cognition process and
architectural model.

Draft Technical Report ITU-T TR-QN-UC “Use cases of quantum networks beyond
QKDN” in TD237/WP3

Based on the deliverable (D1.2) of the ITU-T Focus Group on Quantum Information
Technology for Networks (FG QIT4N), this Technical Report sorts and analyses
use cases of quantum networks beyond QKDN collected from FG QIT4N 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 current
bottlenecks, application scenarios, technical requirements and solutions. This
Technical Report also provides analyses for future applications and potential
standardization requirements.

Draft Supplement ITU-T Y.supp.QKDN-UC “Use cases of quantum key distribution
networks” in TD236/WP3

Based on the deliverable (D2.2) of the ITU-T Focus Group on Quantum Information
Technology for Networks (FG QIT4N), this Supplement consolidates the QKDN use
cases collected from the ITU-T FG QIT4N 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.

Draft Recommendation ITU-T Y.QKDN_SSNreq “Functional requirements for
integration of quantum key distribution network and secure storage network" in
TD238/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
TD239/WP3

This draft Recommendation will study on 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 Y.QKDN-qos-iw-req “Requirements of QoS assurance for QKDN
interworking " in TD339/WP1

This draft Recommendation specifies the high-level and functional requirements
of QoS assurance for quantum key distribution networks (QKDN) interworking, and
the scope of this recommendation is as follows: - Overview of QoS assurance for
QKDN interworking - High-level requirements of QoS assurance for QKDN
interworking - Functional requirements of QoS assurance for QKDN interworking;

Draft Recommendation Y.QKDN-qos-ml-fa “Quantum key distribution networks:
Functional architecture enhancement of machine learning based quality of
service assurance " in TD340/WP1

This Recommendation specifies the functional architecture enhancement of
machine learning based QoS assurance for IMT-2020 network, the scope of this
recommendation is as follows: - Overview of requirements of machine learning
based QoS assurance for QKDN; - Functional architecture enhancement of machine
learning based QoS assurance for QKDN; - Reference points of machine learning
based QoS assurance for QKDN - Procedures of machine learning based QoS
assurance for QKDN;

This Recommendation uses machine learning only in the context of QoS assurance.
Therefore any other use of machine learning is out of scope of this
Recommendation.

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

Draft Technical Report on "Overview for integration of quantum key distribution
network with non-quantum cryptographies” in TD244/WP3

This report provides the overview for integration of quantum key distribution
network with non-quantum cryptographies under three categories as follows: -
QKDN’s relation to end-to-end cryptography service - Service Scenarios for the
integration with non-quantum cryptography (e.g., PKI architecture) -
Implications for standardization activity on Study Group 13

Draft Supplement ITU-T Y.supp.QKDN_sync “Analysis of Time Synchronization in
Quantum Key Distribution Networks” in TD245/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, KM, management, and control layers of QKDN.

Draft Recommendation ITU-T Y.QKDN-TSNfr “Framework for integration of quantum
key distribution network and time sensitive network " in TD246/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 Recommendation ITU-T Y.QKDN-rsrq “Requirements for quantum key
distribution network resilience” in TD247/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-qos-auto-rq “Quantum key distribution
networks – Requirements for autonomic quality of service assurance” in TD344/WP1

The QKDN is expected to be able to provide optimized support for a variety of
different QKD services. The key performance indicators (KPIs) include optimal
latency, accuracy, throughput, and availability for key distribution. However,
one of the challenges of the QKDN is to assure the network performance and
different QoS/QoE requirements of different application scenarios in an
autonomic way. The autonomic ability for QoS in QKDN will support the seamless
intelligent decision-making feedback loop of precise monitoring of status of
managed QKDN resources, intelligent decision-making and necessary
policy-generation based on the monitored QKDN QoS information, and open
programmable enforcement of generated policies. To enable the autonomic QoS
assurance, the requirements of autonomic QoS planning, autonomic QoS
monitoring, autonomic QoS optimization, autonomic QoS provisioning, autonomic
QoS protection and recovery are needed. This draft recommendation specifies the
overview, the high-level requirements and functional requirements of autonomic
QoS assurance for QKDN. The security considerations are also illustrated.

5.Conclusion

SG13 will study the network aspects of QKD. Q16/13 looks 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 new Supplement 74 to ITU-T Y.3000-series Recommendation (formerly
Y.supp.QKDN-roadmap) “Standardization roadmap on Quantum Key Distribution
Networks” (TD100/PLEN); 2) The updated draft Recommendation ITU-T Y.QKDN-iwac
“Quantum key distribution network interworking - architecture” (TD232/WP3); 3)
The updated draft Recommendation ITU-T Y.QKDN-rsfr “Quantum key distribution
networks – overview of resilience” (TD229/WP3); 4) The new Supplement 75 to
ITU-T Y.3000-series Recommendation (formerly TR-QEFN) “Quantum key distribution
networks – Quantum-Enabled Future Networks”; 5) The updated draft
Recommendation ITU-T Y.QKDNi_SDNC “Quantum Key Distribution Network
Interworking – Software Defined Networking Control” (TD233/WP3); 6) The updated
draft Recommendation ITU-T Y.QKDNf_fr “Framework of Quantum Key Distribution
Network Federation” (TD234/WP3); 7) The updated draft Technical Report ITU-T
TR-QN-UC “Use cases of quantum networks beyond QKDN” (TD237/WP3); 8) The
updated draft Supplement ITU-T Y.supp.QKDN-UC “Use cases of quantum key
distribution networks” (TD236/WP3); 9) The updated draft Recommendation ITU-T
Y.QKDN-AMC “Quantum key distribution networks - Requirements and architectural
model for autonomic management and control" (TD235/WP3); 10) The updated draft
Recommendation ITU-T Y.QKDN_SSNreq “Functional requirements for integration of
quantum key distribution network and secure storage network" (TD238/WP3); 11)
The updated draft Recommendation ITU-T Y.QKDN_SSNarch “Functional architecture
for integration of quantum key distribution network and secure storage network"
(TD239/WP3); 12) The updated draft Recommendation ITU-T Y.QKDN-qos-iw-req
“Requirements of QoS assurance for QKDN interworking" (TD339/WP1); 13) The
updated draft Recommendation ITU-T Y.QKDN-qos-ml-fa “Quantum key distribution
networks: Functional architecture enhancement of machine learning based quality
of service assurance" (TD340/WP1).