Liaison statement
LS on work progress on Quantum Key Distribution (QKD) network in SG13 (as of March 2024)

ITU-T SG13 is pleased to inform you of our progress on Quantum Key Distribution
(QKD) topics. SG13 has published 20 Recommendations and 5 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”; - Recommendation ITU-T Y.3819 “Quantum key
distribution networks - requirements and architectural model for autonomic
management and control 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.3800-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”; -
Supplement ITU-T Y.Sup79 to Y.3800-series “Quantum key distribution networks –
Role in end-to-end cryptographic services with non-quantum cryptography”; -
Supplement ITU-T Y.Sup80 to Y.3800-series “Use cases of quantum key
distribution networks”.

1. The items consented at the March 2024 ITU-T Study Group 13 meeting
The draft Recommendations ITU-T Y.QKDNi_SDNC and Y.QKDN-rsrq were consented:

Draft Recommendation ITU-T Y.3820 (ex Y.QKDNi_SDNC) “Quantum Key Distribution
Network Interworking - Software Defined Networking Control” in TD230/PLEN

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.3821 (ex Y.QKDN-rsrq) “Requirements for quantum
key distribution network resilience” in TD231/PLEN)

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.

2. Revised on-going work items after November 2023 SG13 meeting

Draft Recommendation ITU-T Y.QKDNf_fr “Framework of Quantum Key Distribution
Network Federation” in TD503/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-nq-rf “Requirements and framework for
end-to-end QKDN and non-quantum cryptographies services” in TD505/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 TD506/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 "Requirements and framework for
quality of service assurance of end-to-end QKDN and non-quantum cryptography
services" in TD738/WP1

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, requirements and a framework
architecture for quality of service assurance of end-to-end QKDN and
non-quantum cryptography (NQC) services.

Draft Recommendation ITU-T Y.QKDN-qos-auto-rq "Quantum key distribution
networks - Requirements for autonomic quality of service assurance" in TD739/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.

Draft Supplement ITU-T Y.supp.QKDN_sync “Analysis of Time Synchronization in
Quantum Key Distribution Networks” in TD504/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 Supplement ITU-T Y.supp.TC-QN “Technical considerations towards Quantum
Network” in TD507/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.

3. New work items agreed at the March 2024 SG13 meeting

Draft Recommendation ITU-T Y.QKDN-safr "Quantum key distribution networks -
Framework for service awareness" in TD512/WP3

Quantum key distribution network (QKDN) can be regarded as a kind of
cryptographic infrastructure since it supports more and more cryptographic
applications, such as video conference, VoLTE, email, etc. Diversified
cryptographic applications put forward differentiated service requirements for
QKDN, including low deterministic latency, low jitter, high deterministic
availability, and guaranteed key supplies and so on.

With the separation mechanism of QKDN and cryptographic services, the
underlying QKDN network cannot perceive service characteristic information, it
is difficult to identify the SLA guarantee requirements of services. Therefore,
it is necessary to consider service awareness function for QKDN with the
guidance of service awareness, service scheduling and service differentiation
which can aware users, service requirements, QKDN resource and service status
and so on in real time, so as to provide differentiated services. Meanwhile,
it’s valuable to carry out necessary standardization works.

This Recommendation specifies scenarios, requirements and functional model of
service awareness for QKDN.

Draft Recommendation ITU-T Y.QKDN-orfr “Framework for quantum key distribution
network orchestration” in TD516/WP3

This Recommendation will specify an orchestration framework to enhance resource
efficiency of quantum key distribution network (QKDN). It describes QKDN
orchestration with an overview, requirements, reference models, and overall
operational procedures..

Draft Recommendation ITU-T Y.QKDN-rsff “Quantum key distribution networks –
functional framework of resilience” in TD517/WP3

This Recommendation will specify a functional framework of QKDN resilience to
enable seamless key supply even in the case of failures. It describes the
functional configurations and operational procedures for protection and
recovery of key supply.

Draft Recommendation ITU-T Y.QKD-IPSec-fr “Framework for integration of quantum
key distribution and IPSec” in TD513/WP3

With the diversity of network services and the demand for security, it is
necessary to use QKD to ensure the security of user networks. Therefore, it is
promising to implement standardization work for the integration of QKDN and
user networks. Combining QKD with IPsec can achieve better end-to-end
encryption. QKD provides secure key distribution based on quantum mechanics to
resist future quantum computing attacks. IPsec provides traditional encryption
and authentication mechanisms. By combining QKDN and IPsec, not only does it
achieve strong defence against quantum computing attacks, but it also provides
comprehensive protection from classical encryption and identity verification.

This Recommendation will carry out standardization study and specify framework
for integration of QKD and IPSec, including the overview of QKD and IPSec
integration, application modes of QKD and IPSec integration, reference model of
QKD and IPSec integration, requirements of QKD and IPSec integration and
security considerations.

Draft Recommendation ITU-T Y.QKDN_qos_auto_fa: “Quantum key distribution
networks – Functional architecture for autonomic quality of service assurance”
in TD742/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.

This draft recommendation specifies the overview, functional architecture,
reference points and basic operational procedures of autonomic QoS assurance
for QKDN.

Draft Technical Report ITU-T TR.SQKDN “Standardization consideration of
Satellite-based QKDN” in TD515/WP3

This document reviews progress in satellite-based QKDN and related documents of
satellite-based QKDN from standards development organizations. The introduction
of use cases and general technical information of satellite-based QKDN are
discussed. In addition, gap analysis and suggestions on the standardization of
satellite-based QKDN are given in this technical report for reference purposes.

Draft Recommendation ITU-T Y.3804 Revision “Quantum key distribution networks –
Control and management” in TD510/WP3

To realize secure, stable, efficient, and robust operations of and services by
a quantum key distribution (QKD) network as well as to manage a QKD network
(QKDN) as a whole and support user network management, Recommendation ITU-T
Y.3804 specifies functions and procedures for QKDN control and management based
on the requirements specified in Recommendation ITU T Y.3801. This revision of
the Recommendation adds the description of reference point Mx and the
management procedures in Subscription-Notification information exchange.

Draft Recommendation ITU-T Y.3808 Revision “Integration of quantum key
distribution network and secure storage network” in TD514/WP3

Recommendation ITU-T Y.3808 provides an overview of secure storage networks
(SSNs) for quantum key distribution networks (QKDNs). It specifies the
functional requirements, functional architecture model, reference points and
operational procedures for SSNs.

This revision of the Recommendation will merge the detailed functional
requirements and architecture from the two ongoing work items, i.e.,
Y.QKDN_SSNreq and Y.QKDN_SSNarch, which are terminated in this meeting.

4. 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 Y.3820 (ex Y.QKDNi_SDNC) “Quantum Key Distribution Network
Interworking - Software Defined Networking Control” (TD230/PLEN); 2) The
consented Y.3821 (ex Y.QKDN-rsrq) “Requirements for quantum key distribution
network resilience” (TD231/PLEN); 3) The updated Y.QKDNf_fr “Framework of
Quantum Key Distribution Network Federation” (TD503/WP3); 4) The updated
Y.QKDN-nq-rf “Requirements and framework for end-to-end QKDN and non-quantum
cryptographies services” (TD505/WP3); 5) The updated Y.QKD-TLS “Quantum Key
Distribution integration with Transport Layer Security 1.3” (TD506/WP3); 6) The
updated Y.QKDN-nq-qos-rf "Requirements and framework for quality of service
assurance of end-to-end QKDN and non-quantum cryptography services"
(TD738/WP1); 7) The updated Y.QKDN-qos-auto-rq "Quantum key distribution
networks - Requirements for autonomic quality of service assurance"
(TD739/WP1); 8) The updated Y.supp.QKDN_sync “Analysis of Time Synchronization
in Quantum Key Distribution Networks” (TD504/WP3); 9) The updated Y.supp.TC-QN
“Technical considerations towards Quantum Network” (TD507/WP3)