Internet-Draft Use of ML-DSA in TLS 1.3 May 2026
Hollebeek, et al. Expires 7 November 2026 [Page]
Workgroup:
Transport Layer Security
Internet-Draft:
draft-ietf-tls-mldsa-03
Published:
Intended Status:
Informational
Expires:
Authors:
T. Hollebeek
DigiCert
S. Schmieg
Google
B. E. Westerbaan
Cloudflare

Use of ML-DSA in TLS 1.3

Abstract

This memo specifies how the post-quantum signature scheme ML-DSA (FIPS 204) is used for authentication in TLS 1.3.

About This Document

This note is to be removed before publishing as an RFC.

The latest revision of this draft can be found at https://tlswg.github.io/tls-mldsa/draft-ietf-tls-mldsa.html. Status information for this document may be found at https://datatracker.ietf.org/doc/draft-ietf-tls-mldsa/.

Discussion of this document takes place on the Transport Layer Security Working Group mailing list (mailto:tls@ietf.org), which is archived at https://mailarchive.ietf.org/arch/browse/tls/. Subscribe at https://www.ietf.org/mailman/listinfo/tls/.

Source for this draft and an issue tracker can be found at https://github.com/tlswg/tls-mldsa.

Status of This Memo

This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79.

Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet-Drafts is at https://datatracker.ietf.org/drafts/current/.

Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress."

This Internet-Draft will expire on 7 November 2026.

1. Introduction

ML-DSA is a post-quantum module-lattice-based digital signature algorithm standardised by NIST in [FIPS204].

This memo specifies how ML-DSA can be negotiated for authentication in TLS 1.3 via the signature_algorithms and signature_algorithms_cert extensions.

2. Conventions and Definitions

The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all capitals, as shown here.

3. ML-DSA SignatureScheme Values

As defined in [RFC8446], the SignatureScheme namespace is used for the negotiation of signature scheme for authentication via the signature_algorithms and signature_algorithms_cert extensions. This document maps three new SignatureScheme values for the three ML-DSA parameter sets listed in Section 4, Table 1 of [FIPS204] to the SignatureAlgorithmIdentifiers from [RFC9881] as follows as follows.

Table 1: SignatureSchemes for ML-DSA
SignatureScheme FIPS 204 Signature AlgorithmIdentifier
mldsa44(0x0904) ML-DSA-44 id-ML-DSA-44 (2.16.840.1.101.3.4.3.17)
mldsa65(0x0905) ML-DSA-65 id-ML-DSA-65 (2.16.840.1.101.3.4.3.18)
mldsa87(0x0906) ML-DSA-87 id-ML-DSA-87 (2.16.840.1.101.3.4.3.19)

Note that these are different from the HashML-DSA pre-hashed variants defined in Section 5.4 of [FIPS204], which are not used here because of the reasons laid out in Section 8.3 of [RFC9881].

3.1. Certificate Chain

For the purpose of signalling support for signatures on certificates as per Section 4.2.3 of [RFC8446], these values indicate support for signing using the given AlgorithmIdentifier shown in Table 1 as defined in [RFC9881].

3.2. Handshake Signature

When one of those SignatureScheme values is used in a CertificateVerify message, then the signature MUST be computed and verified as specified in Section 4.4.3 of [RFC8446], using Algorithm 2 (ML-DSA.Sign) and Algorithm 3 (ML-DSA.Verify) of [FIPS204] respectively. The context (ctx) parameter MUST be the empty string. Note that the context parameter of FIPS 204 is different from the context string of Section 4.4.3 of [RFC8446].

The corresponding end-entity certificate MUST use the corresponding AlgorithmIdentifier from Table 1 in its SubjectPublicKeyInfo.

The context parameter defined in [FIPS204] Algorithm 2 and 3 MUST be the empty string. Note that the context parameter of FIPS 204 is different from the context string of Section 4.4.3 of [RFC8446].

3.3. TLS 1.2

The schemes defined in this document MUST NOT be used in TLS 1.2 [RFC5246] or earlier versions. A peer that receives ServerKeyExchange or CertificateVerify message in a TLS 1.2 connection with schemes defined in this document MUST abort the connection with an illegal_parameter alert.

4. Security Considerations

The security considerations of [RFC8446] (eg. Appendices C.2 and E.1 of [RFC8446] and Section 4.4.3 of [RFC8446]) and [FIPS204] (Section 3.4 and 3.6) apply.

5. IANA Considerations

This document requests new entries to the TLS SignatureScheme registry, according to the procedures in Section 6 of [RFC9847].

Table 2
Value Description Recommended Reference
0x0904 mldsa44 N This document.
0x0905 mldsa65 N This document.
0x0906 mldsa87 N This document.

6. References

6.1. Normative References

[FIPS204]
"Module-lattice-based digital signature standard", National Institute of Standards and Technology (U.S.), DOI 10.6028/nist.fips.204, , <https://doi.org/10.6028/nist.fips.204>.
[RFC2119]
Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, , <https://www.rfc-editor.org/rfc/rfc2119>.
[RFC8174]
Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, , <https://www.rfc-editor.org/rfc/rfc8174>.
[RFC8446]
Rescorla, E., "The Transport Layer Security (TLS) Protocol Version 1.3", RFC 8446, DOI 10.17487/RFC8446, , <https://www.rfc-editor.org/rfc/rfc8446>.
[RFC9881]
Massimo, J., Kampanakis, P., Turner, S., and B. E. Westerbaan, "Internet X.509 Public Key Infrastructure -- Algorithm Identifiers for the Module-Lattice-Based Digital Signature Algorithm (ML-DSA)", RFC 9881, DOI 10.17487/RFC9881, , <https://www.rfc-editor.org/rfc/rfc9881>.

6.2. Informative References

[RFC5246]
Dierks, T. and E. Rescorla, "The Transport Layer Security (TLS) Protocol Version 1.2", RFC 5246, DOI 10.17487/RFC5246, , <https://www.rfc-editor.org/rfc/rfc5246>.
[RFC9847]
Salowey, J. and S. Turner, "IANA Registry Updates for TLS and DTLS", RFC 9847, DOI 10.17487/RFC9847, , <https://www.rfc-editor.org/rfc/rfc9847>.

Acknowledgments

Thanks to Alicja Kario, John Mattsson, Rebecca Guthrie, Alexander Bokovoy, Niklas Block, Ryan Appel, Loganaden Velvindron, David Benjamin, Viktor Dukhovni, Rob Sayre, Daniel Van Geest, Martin Thomson, Wang Guilin, and Nick Sullivan for their review and feedback.

Authors' Addresses

Tim Hollebeek
DigiCert
Sophie Schmieg
Google
Bas Westerbaan
Cloudflare