Post-Quantum Use In Protocols L. Li
Internet-Draft F. Liu
Intended status: Standards Track Huawei
Expires: 3 September 2025 2 March 2025
PQC Escape Message for Dynamic Migration
draft-li-pquip-escape-message-00
Abstract
In this contribution, a design of escape message mechanism is
proposed, where the service provider sends an escape message to the
service consumer using existing non-PQC connection and then starts to
re-establish the quantum-safe protocol. The proposed escape message
can potentially be used in a variety of protocols, including IPsec,
TLS, or between the air interface of a cellpohone and a network
device. We believe that for largely deployed networks and entities,
escape messages can be provided as a plan B for legacy devices of the
service provider and consumer that may not able to complete post-
quantum migration in advance. It can mitigate negative migration
impacts when potential Q-day occurs.
Status of This Memo
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Requirements Language . . . . . . . . . . . . . . . . . . . . 3
3. System Architecture . . . . . . . . . . . . . . . . . . . . . 3
4. Message and Mechanism Design . . . . . . . . . . . . . . . . 4
4.1. Requirements . . . . . . . . . . . . . . . . . . . . . . 4
4.2. Basic steps of escape message . . . . . . . . . . . . . . 4
5. Escape message example: the UE and Network in teleco
network . . . . . . . . . . . . . . . . . . . . . . . . . 5
6. Escape message example: IPsec/IKEv2 . . . . . . . . . . . . . 5
7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 6
8. Security Consideration . . . . . . . . . . . . . . . . . . . 6
9. References . . . . . . . . . . . . . . . . . . . . . . . . . 6
9.1. Normative Reference . . . . . . . . . . . . . . . . . . . 6
9.2. Informative References . . . . . . . . . . . . . . . . . 7
Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . 7
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 7
1. Introduction
The post-quantum migration should be gradual in largely deployed
networks and entities since one of the important feature of these
networks such as telecom network is that a large number of legacy
entities and devices have been deployed on the always-live network.
The migration may cause complex effects in terms of confusing
interfaces and reference point.
Considering the increased computational and payload burden of legacy
equipment, many stakeholders may take risks and not be willing to
embed a large number of equipments to complete the migration ahead of
time. Considering billions of cellphones (aka., UE), hundreds of
thousands of network entities, we propose to embed the post-quantum
migration preparation gradually in advance, and to dynamically
trigger and complete the post-quantum migration as required by extra
messages and service mechanisms.
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Therefore, regarding future quantum attacks (aka, Q-day attacks such
as Shor's algorithm [shor]), one of the practical approaches is to
notify entities to dynamically perform post-quantum migration using a
new message, which we called the PQC escape message. The name was
inspired by the history of the ESC key [ISO9995] in the keyboard,
when ESC key is originally used for switching different mode of vi
family [ESCKEY].
An PQC escape message should be sent in a proper procedure, for
example, periodically or broadcast. In addition, except sending the
escape message as a simply notification, it can also contain
additional usage. It will be discussed in the session of the message
design.
We believe that the need for escape messages exists widely in a
variety of complex systems, not limit to largely deployed networks
such as telecom networks. It is recommended to provide guidance of
the format of the escape message.
2. Requirements Language
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in [RFC2119].
3. System Architecture
The PQC escape message should be deployed between the service
provider and the consumer. In general, the service provider and
consumer are only concepts, multiple servers or consumers are also
supported as long as having an established secure connection (e.g.,
IPsec [RFC4301], TLS [RFC8446], etc.).
+--------+ +---------+
| | | |
|Service | | Service |
|Consumer|<------------------------------------------->| Provider|
| | Communicate with current security | |
| | Connection (tls, ipsec, etc.) | |
+--------+ +---------+
Figure 1 System architecture applied escape message
The service consumer for example can be a UE, an APP client, a
security gateway. The service provider for example can be a network
function, an APP server, or a security gateway.
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4. Message and Mechanism Design
4.1. Requirements
Escape messages should be designed to be as simple and efficient
between service providers and consumers. Some requirements are
listed as follows:
* 1. the message shall be dedicated for instruction to complete a
live quantum migration. A dedicated message format helps the
device identify the message rapidly. In term of the
implementation level, the device can enter a dedicated migration
mode to improve the success rate and shorten the response time.
* 2. the escape message shall contain a common security protection
design including the integrity protection. This prevents
attackers from sending false indications and causing the device to
enter the migration state accidently.
* 3. the message shall be a standardized message format. A pre-
shared key may be configured on both sides of the device to be
migrated, which can be used for the protection of migration and a
furtherly negotiation a post-quantum algorithm key. The sepcific
format can be discussed in dedicated working group which are not
in the scope of this docuement.
The pre-shared key can be either a dedicated pre-shared key.
Optionally, it can also be the symmetric (pre-shared) key already
used in the currently connection of TLS or IPsec, etc. Specifically,
the following two mode can be used as options.
4.2. Basic steps of escape message
From the perspective of IETF PQUIP and this use case, the following
analysis can be considered.
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+----------+ +---------+
| | <---------------------------------------- | |
| | 1. Send Escape message | |
| | | |
| | ---------------------------------------> | |
| Consumer |2. Response Escape message and start migration| Service |
| | |Provider |
| | +--------------------------------------+ | |
| | | 3.Negotiate new security context | | |
| |---| to establish PQC secure connection |---| |
| | +--------------------------------------+ | |
+----------+ +---------+
Figure 2. Basic steps of escape message
The following steps shall be performed between consumer and service
provider:
* 1. The service provider sends escape message to the consumer.
* 2. The consumer responses the escape message and starts to PQC
migration.
* 3. The consumer and service provider negotiate the new PQC
security context and to establish PQC security connection. There
are several ways to negotiate with new PQC security context. For
example, If the consumer and service provider have established an
IPsec connection through traditional IKE [RFC7296], the multiple
key exchanges of IKEv2 as defined in RFC 9370 [RFC9370] can be
used to re-negotiate a new quantum-safe security key after
receiving the escape message.
The consumer and service provider preconfigure the escape message.
During the migration point (for example, service provider detected
the quantum attack in Q-day, or as instructions of the system
administrator). The service provider can send the escape message
with above flows to consumer. Then, the consumer will response
escape message to start the PQC migration. Finally, the consumer and
the service provider shall start to negotiate new security context of
including ML-KEM, ML-DSA or hybrid key exchanges, etc.
5. Escape message example: the UE and Network in teleco network
/*TODO
6. Escape message example: IPsec/IKEv2
/*TODO
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7. IANA Considerations
This document has no IANA considerations.
8. Security Consideration
Escape messages are a compromise approach for dynamic PQC migration,
usually it is expected after an attack has been discovered. It is
still recommended that quantum migration should be performed in
advance. Escape can be a plan B.
During the escape message procedure, Although basic steps can be
implemented easily, it is worth to say that the key being used in
non-PQC TLS or IPsec may already be leaked during the key exchange
phase because of Q-day attacks. For example, assume that an attacker
has captured the key during the establishement of non-PQC TLS or
IPsec connection, and uses a quantum attack (e.g., Harvest Now,
Decrypt Later" (HNDL) attack attack). In this case, the attacker can
obtain the information and data in the connection, including
subsequent escape messages and PQC security context negotiation
content, which potential brings security risks.
/*TODO: Consideration of security enhancement when potential non
quantum-safe keys already be leaked before triggering escape.
9. References
9.1. Normative Reference
[ISO9995] ISO/IEC, "Information technology — Keyboard layouts for
text and office systems", ISO/IEC 9995-1:2009, ISO/IEC JTC
1/SC 35, October 2009,
<https://www.iso.org/standard/51645.html>.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<https://www.rfc-editor.org/rfc/rfc2119>.
[RFC4301] Kent, S. and K. Seo, "Security Architecture for the
Internet Protocol", RFC 4301, DOI 10.17487/RFC4301,
December 2005, <https://www.rfc-editor.org/info/rfc4301>.
[RFC7296] Kaufman, C., Hoffman, P., Nir, Y., Eronen, P., and T.
Kivinen, "Internet Key Exchange Protocol Version 2
(IKEv2)", STD 79, RFC 7296, DOI 10.17487/RFC7296, October
2014, <https://www.rfc-editor.org/info/rfc7296>.
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[RFC8446] Rescorla, E., "The Transport Layer Security (TLS) Protocol
Version 1.3", RFC 8446, DOI 10.17487/RFC8446, August 2018,
<https://www.rfc-editor.org/info/rfc8446>.
[RFC9370] Tjhai, CJ., Tomlinson, M., Bartlett, G., Fluhrer, S., Van
Geest, D., Garcia-Morchon, O., and V. Smyslov, "Multiple
Key Exchanges in the Internet Key Exchange Protocol
Version 2 (IKEv2)", RFC 9370, DOI 10.17487/RFC9370, May
2023, <https://www.rfc-editor.org/info/rfc9370>.
9.2. Informative References
[ESCKEY] Wikipedia, "the ESC key", 10 February 2025,
<https://en.wikipedia.org/wiki/Esc_key#References>.
[shor] Shor, P.W., "Algorithms for Quantum Computation: Discrete
Logarithms and Factoring", DOI 10.1109/SFCS.1994.365700, 6
August 2002, <https://ieeexplore.ieee.org/document/365700/
authors#authors>.
Acknowledgments
TODO
Authors' Addresses
Lun Li
Huawei
Email: lilun20@huawei.com
Faye Liu
Huawei
Email: liufei19@huawei.com
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