Complete PQC Object Identifier (OID) Registry

As NIST, IETF, and ISO finalize PQC algorithms, each scheme is assigned a unique Object Identifier (OID) for use in X.509 certificates, PKCS#8 keys, CMS, TLS, and COSE/JOSE structures.

This post provides a consolidated registry of PQC OIDs — covering the standardized ML-DSA (Dilithium), SLH-DSA (SPHINCS+), and ML-KEM (Kyber) algorithms, plus supporting hash functions and hybrid structures.


🔑 Why This Matters

  • Certificates: OIDs appear in AlgorithmIdentifiers for signatures and public keys.
  • Interoperability: Different vendors must agree on these identifiers.
  • Migration: PQC-hybrid certificates require careful OID management.

📂 PQC Algorithm OIDs

1. ML-DSA (Dilithium) — Post-Quantum Digital Signature

Assigned under the NIST digital signature arc: 2.16.840.1.101.3.4.3.x

Algorithm VariantOIDNotes
ML-DSA-44 (Dilithium-2)2.16.840.1.101.3.4.3.17NIST Category 2
ML-DSA-65 (Dilithium-3)2.16.840.1.101.3.4.3.18NIST Category 3
ML-DSA-87 (Dilithium-5)2.16.840.1.101.3.4.3.19NIST Category 5

Use cases: X.509 signatures, code signing, document signing.


2. SLH-DSA (SPHINCS+) — Stateless Hash-Based Signature

Assigned under the NIST digital signature arc: 2.16.840.1.101.3.4.3.2x

Algorithm VariantOIDNotes
SLH-DSA-SHA2-128s2.16.840.1.101.3.4.3.20SHA-256, small, cat 1
SLH-DSA-SHA2-128f2.16.840.1.101.3.4.3.21SHA-256, fast, cat 1
SLH-DSA-SHA2-192s2.16.840.1.101.3.4.3.22SHA-256, cat 3
SLH-DSA-SHA2-192f2.16.840.1.101.3.4.3.23SHA-256, fast, cat 3
SLH-DSA-SHA2-256s2.16.840.1.101.3.4.3.24SHA-256, cat 5
SLH-DSA-SHA2-256f2.16.840.1.101.3.4.3.25SHA-256, fast, cat 5
SLH-DSA-SHAKE-128s2.16.840.1.101.3.4.3.26SHAKE128, cat 1
SLH-DSA-SHAKE-128f2.16.840.1.101.3.4.3.27SHAKE128, fast, cat 1
SLH-DSA-SHAKE-192s2.16.840.1.101.3.4.3.28SHAKE128, cat 3
SLH-DSA-SHAKE-192f2.16.840.1.101.3.4.3.29SHAKE128, fast, cat 3
SLH-DSA-SHAKE-256s2.16.840.1.101.3.4.3.30SHAKE256, cat 5
SLH-DSA-SHAKE-256f2.16.840.1.101.3.4.3.31SHAKE256, fast, cat 5

Use cases: Long-term archival signatures (very conservative).


3. ML-KEM (Kyber) — Post-Quantum Key Encapsulation Mechanism

Assigned under the NIST encryption/KEM arc: 2.16.840.1.101.3.4.1.5x

Algorithm VariantOIDNotes
ML-KEM-512 (Kyber-512)2.16.840.1.101.3.4.1.55NIST security cat 1
ML-KEM-768 (Kyber-768)2.16.840.1.101.3.4.1.56NIST security cat 3
ML-KEM-1024 (Kyber-1024)2.16.840.1.101.3.4.1.57NIST security cat 5

Use cases: TLS key exchange, CMS encryption, VPNs.


📚 Supporting OIDs for PQC

Hash Functions

Defined in the NIST hash arc: 2.16.840.1.101.3.4.2.x

  • 2.16.840.1.101.3.4.2.11 → SHAKE128
  • 2.16.840.1.101.3.4.2.12 → SHAKE256
  • 2.16.840.1.101.3.4.2.8 → SHA3-256
  • 2.16.840.1.101.3.4.2.9 → SHA3-384
  • 2.16.840.1.101.3.4.2.10 → SHA3-512

Used inside SLH-DSA and sometimes in hybrid constructions.


Hybrid / Composite OIDs

Still draft in IETF LAMPS:

  • Composite signature OID → id-composite arc
  • Hybrid OIDs → defined as concatenations (RSA/ECDSA + PQC)

These are not final yet but will be essential for PKI migration strategies.


✅ Key Takeaways

  • Final OIDs for PQC are now part of the NIST OID tree under 2.16.840.1.101.3.4.
  • You should use ML-DSA, SLH-DSA, and ML-KEM OIDs in new certificate and TLS deployments.
  • Expect hybrid OIDs to be finalized soon by IETF for transitional PKI.

👉 With this registry, you have a one-stop lookup for all PQC OIDs in certificates, signatures, and KEMs.

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