CRYSTALS-Dilithium (ML-DSA, FIPS 204) explained for developers
CRYSTALS-Dilithium — standardized by NIST in 2024 as ML-DSA (FIPS 204) — is the primary post-quantum digital signature scheme. It replaces ECDSA and RSA signatures, which a large quantum computer would break.
How it works (briefly)
Dilithium is lattice-based: its security rests on the hardness of problems over module lattices (Module-LWE and Module-SIS), which have no known efficient quantum attack. You generate a keypair, sign a message with the secret key, and anyone verifies with the public key — the same shape as classical signatures, with different math underneath.
The practical numbers
For Dilithium-2 (ML-DSA-44): the public key is ~1.3 KB, the signature ~2.4 KB. That is larger than ECDSA, so you budget extra bandwidth and storage, but signing and verification are fast. On-chain EVM verification is expensive because there are no native precompiles — which is why a purpose-built post-quantum L1 plus a signing API is useful.
When to use it
Use Dilithium for anything that must stay verifiable for years: software signing, document notarization, audit logs, and AI decision records. It is resistant to all known classical and quantum attacks per NIST — not unbreakable, but the migration standard available today.
Try it yourself — live, free, verifiable in 30 seconds:
Sign with Dilithium via the PQC API →