TLS 1.3 Extension for Using Certificates with an External Pre-Shared Key

Metadata

Publisher: IETF
Doc Type: Standard
Pages: 13
Abstract: This document specifies a TLS 1.3 extension that allows TLS clients and servers to authenticate with certificates and provide confidentiality based on encryption with a symmetric key from the usual key agreement algorithm and an external pre-shared key (PSK). This Standards Track RFC obsoletes RFC 8773, which was an Experimental RFC.
Publication Date: 2026-07-01
Status Note: Proposed Standard
DOI: 10.17487/RFC9973
Link: https://doi.org/10.17487/RFC9973
Author(s): Russ Housley
Keyword(s): Cryptography, Pre-shared Key

Latest version of IETF RFC 9973

Document Versions — IETF RFC 9973

▶ IETF RFC 9973 (2026-07-01)

THIS DOC [ACTIVE] [LATEST VERSION]

Normative Reference(s)

IETF RFC 2119 [Active*]
IETF RFC 7250 [Active*]
IETF RFC 8174 [Active*]
IETF RFC 9846 [Active*]

Bibliographic Reference(s)

10.1145-6490.6503 — GGM1986 EXTERNAL
Internet Assigned Numbers Authority [Active, Versionless]
Krawczyk, H., "A Unilateral-to-Mutual Authentication Compiler for Key Exchange (with Applications to Client Authentication in TLS 1.3)", Cryptology ePrint Archive, Paper 2016/711, 2016, <https://eprint.iacr.org/2016/711>. EXTERNAL
IETF RFC 2104 [Active, Amended*]
IETF RFC 4086 [Active*]
IETF RFC 5246 [Superseded*]
IETF RFC 8773 [Superseded*]
IETF RFC 9258 [Active*]
IETF RFC 9849 [Active*]
IETF RFC 9958 [Active*]
IETF RFC 9966 [Active*]

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Supersedes:

IETF RFC 8773 [Superseded*]

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<span class="citation"><cite>IETF RFC 9973</cite>, TLS 1.3 Extension for Using Certificates with an External Pre-Shared Key. Available at <a href="https://doi.org/10.17487/RFC9973" target="_blank" rel="noopener">https://doi.org/10.17487/RFC9973</a></span>

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IETF RFC 9973, TLS 1.3 Extension for Using Certificates with an External Pre-Shared Key
doi: 10.17487/RFC9973
url: https://doi.org/10.17487/RFC9973

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<li>
<cite id="bib-rfc9973">IETF RFC 9973</cite>, TLS 1.3 Extension for Using Certificates with an External Pre-Shared Key
<span class="doi">10.17487/RFC9973</span>
</li>