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Vol. 1 · Ed. 2026
CyberGlossary
Entry № 252

CRYSTALS-Dilithium

What is CRYSTALS-Dilithium?

CRYSTALS-DilithiumA lattice-based digital-signature scheme standardized by NIST as FIPS 204 (ML-DSA) in August 2024 and intended as the post-quantum replacement for RSA, DSA, and ECDSA signatures.


CRYSTALS-Dilithium is a digital-signature scheme built on the hardness of Module Learning With Errors (MLWE) and Module Short Integer Solution (MSIS) over structured lattices. It uses Fiat-Shamir with aborts and offers fast verification, with public keys around 1.3-2.6 kB and signatures around 2.4-4.6 kB depending on parameter set. NIST finalized it as FIPS 204 (ML-DSA) in August 2024 with parameter sets ML-DSA-44, ML-DSA-65, and ML-DSA-87 covering security categories 2, 3, and 5. It is the primary signature algorithm in NIST's PQC portfolio and is being integrated into X.509 PKI, code-signing pipelines, and hybrid TLS certificates.

Examples

  1. 01

    Used for ML-DSA-65 certificates in early PQC X.509 pilots by Cloudflare and AWS.

  2. 02

    Selected as the default PQ signature in modern code-signing toolchains alongside SLH-DSA.

Frequently asked questions

What is CRYSTALS-Dilithium?

A lattice-based digital-signature scheme standardized by NIST as FIPS 204 (ML-DSA) in August 2024 and intended as the post-quantum replacement for RSA, DSA, and ECDSA signatures. It belongs to the Cryptography category of cybersecurity.

What does CRYSTALS-Dilithium mean?

A lattice-based digital-signature scheme standardized by NIST as FIPS 204 (ML-DSA) in August 2024 and intended as the post-quantum replacement for RSA, DSA, and ECDSA signatures.

How does CRYSTALS-Dilithium work?

CRYSTALS-Dilithium is a digital-signature scheme built on the hardness of Module Learning With Errors (MLWE) and Module Short Integer Solution (MSIS) over structured lattices. It uses Fiat-Shamir with aborts and offers fast verification, with public keys around 1.3-2.6 kB and signatures around 2.4-4.6 kB depending on parameter set. NIST finalized it as FIPS 204 (ML-DSA) in August 2024 with parameter sets ML-DSA-44, ML-DSA-65, and ML-DSA-87 covering security categories 2, 3, and 5. It is the primary signature algorithm in NIST's PQC portfolio and is being integrated into X.509 PKI, code-signing pipelines, and hybrid TLS certificates.

How do you defend against CRYSTALS-Dilithium?

Defences for CRYSTALS-Dilithium typically combine technical controls and operational practices, as detailed in the full definition above.

What are other names for CRYSTALS-Dilithium?

Common alternative names include: Dilithium, ML-DSA, FIPS 204.

Related terms

See also