Archivecryptography
ML-DSA and the Signature Migration
Dilithium is now ML-DSA. Larger signatures, different performance, and a hybrid period ahead.
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ML-DSA (FIPS 204, from CRYSTALS-Dilithium) is the standardized lattice signature scheme. It replaces ECDSA/Ed25519 in a post-quantum world, with different sizes and performance.
Sizes
- Public key: ~1.3 KB
- Signature: ~2.4 KB
- Secret key: ~2.5 KB
Compare Ed25519: 32-byte keys, 64-byte signatures. Certificates and handshakes grow; some constrained protocols will need redesign.
Performance
Signing and verification are fast on modern CPUs, but key generation and signing are heavier than Ed25519. Verification is cheap enough for most services.
Migration approach
- Run hybrid certificates (classical + PQ) during the transition.
- Keep an algorithm identifier in the protocol; do not assume a fixed signature size.
- Budget for larger handshakes, especially in TLS and firmware.
Takeaway: PQ signatures are ready for testing and hybrid deployment. The hard part is protocol and certificate plumbing, not the math.