IETF Post-Quantum Cryptography Protocol Standards

ActiveGlobalStandard
Effective date
May 1, 2018
Published date
May 1, 2018

Summary

The IETF has standardized how post-quantum cryptographic algorithms are deployed in internet protocols including TLS 1.3, X.509 certificates, CMS, and SSH. Published RFCs include RFC 8391 (XMSS), RFC 8554 (LMS/HSS), and RFC 9370 (ML-KEM in TLS 1.3). Active work in the LAMPS working group has produced X.509 certificate profile RFCs for ML-DSA and SLH-DSA. These protocol-level standards are essential for real-world PQC deployment across internet infrastructure.

PKI impact

High riskTLS/SSLRoot CAEmail/S-MIMECode Signing

IETF standards define the exact wire format and X.509 certificate structure required for PQC interoperability across the internet. RFC 9370 (TLS/SSL), and LAMPS WG X.509 profile RFCs for ML-DSA and SLH-DSA are the normative references every PKI operator must implement to issue and validate PQC certificates in standard protocols.

Migration hints

  • Enable RFC 9370 ML-KEM key exchange in TLS 1.3 by updating TLS library dependencies — most production stacks (OpenSSL 3.5+, BoringSSL) now support it — before issuing PQC authentication certificates to ensure key exchange compatibility.
  • Issue ML-DSA and SLH-DSA certificates using the OIDs and X.509 extensions defined in IETF LAMPS WG RFCs; non-standard OIDs will cause validation failures in compliant relying parties.
  • For S/MIME and CMS, track IETF LAMPS WG progress on ML-DSA and ML-KEM CMS profiles to ensure certificate issuance aligns with finalized RFC formats before deployment.
  • Validate RFC 8391 (XMSS) and RFC 8554 (LMS) implementation compliance in your firmware signing pipeline against the published test vectors before production use.

Trust chain considerations

  • Root CAs must use IETF LAMPS WG-defined X.509 profiles for ML-DSA to issue interoperable PQC trust anchors; deviating from these profiles will cause chain validation failures in compliant relying parties.
  • X.509 profile RFCs for ML-DSA and SLH-DSA were published in 2025 — verify your CA software supports the finalized OIDs and extension profiles before mass certificate issuance.

Milestones (2)

DeadlineLabelTypeHardNotes
Jun 1, 2025ML-KEM in TLS 1.3 RFC publishedFull ComplianceRFC 9370 published June 2025, standardizing ML-KEM key exchange in TLS 1.3.
Sep 1, 2025ML-DSA and SLH-DSA X.509 certificate RFCs publishedFull ComplianceIETF LAMPS WG published X.509 certificate profile RFCs for ML-DSA and SLH-DSA in 2025.

Algorithm references (5)

  • XMSSSP 800-208Recommended

    Replaces: RSA, ECDSA

    Standardized in RFC 8391 (2018). Recommended for stateful hash-based signature use cases requiring long-term security guarantees.

  • LMS / HSSSP 800-208Recommended

    Replaces: RSA, ECDSA

    Standardized in RFC 8554 (2019). Recommended for stateful hash-based signatures, particularly firmware and software signing.

  • ML-KEMFIPS 203Recommended

    Replaces: RSA, ECDH

    Standardized for use in TLS 1.3 via RFC 9370 (2025). Defines ML-KEM key exchange for TLS connections.

  • ML-DSAFIPS 204Recommended

    Replaces: RSA, ECDSA

    X.509 certificate profiles for ML-DSA standardized by IETF LAMPS WG in 2025.

  • SLH-DSAFIPS 205Recommended

    Replaces: RSA, ECDSA

    X.509 certificate profiles for SLH-DSA standardized by IETF LAMPS WG in 2025.

Changelog (4)

DateTypeDescription
Jun 1, 2025StatusRFC 9370 published, standardizing ML-KEM for TLS 1.3 key exchange. IETF LAMPS WG simultaneously published X.509 certificate profile RFCs for ML-DSA and SLH-DSA, completing core protocol-layer PQC standardization.
Jul 1, 2024AmendmentIETF LAMPS and TLS working groups published updated drafts for ML-KEM in TLS 1.3 and ML-DSA/SLH-DSA in X.509 certificates following NIST FIPS 203/204/205 finalization.
Feb 1, 2019NewRFC 8554 published, standardizing LMS/HSS stateful hash-based signature scheme for internet use.
May 1, 2018NewRFC 8391 published, standardizing XMSS stateful hash-based signature scheme for internet use.

Issuer

Internet Engineering Task ForceIETF

Type: STANDARDS BODY

Region: Global

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