Post Quantum Signatures in a Browser with JavaScript

NIST has now standardized Dilithium with FIPS 204 (Module-Lattice-Based Digital Signature Standard — ML-DSA) for a PQC signature. The ML-DSA methods are ML-DSA-44 (128-bit security), ML-DSA-65 (192-bit security) and ML-DSA-87 (256-bit security).

With a digital signature, we can prove the integrity of a message, and also the identity of the sender. In this, Bob will take a hash of the message, and then create a signature with his private key. He then sends this signature with the message, and Alice will check the signature with his public key. It is important that we can trust Bob’s public key, so we typically sign it with the private key of Trent, of which Alice will check the signature of Trent for the validity of Bob’s public key.

For ECDSA, RSA, Ed25519 and Ed448 we have:

Method        Public key size (B) Private key size (B)  Signature size (B)  Security level
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Ed25519       32                  32                    64           1 (128-bit) EdDSA
Ed448         57                  57                   112           3 (192-bit) EdDSA…