ML-DSA Sign & Verify Online | Post-Quantum Signatures (FIPS 204)

This tool runs the full FIPS 204 (ML-DSA) workflow in your browser using the @noble/post-quantum library, loaded as a separate lazy chunk. Generate a key pair for any of the three parameter sets (ML-DSA-44/65/87), sign a message with the secret key, then verify the signature with the public key — all locally, no data leaves your device. Post-quantum keys and signatures are larger than classical ones (1–5 KB), so the tool validates every input against exact FIPS 204 byte lengths and supports both hex and Base64 encoding.

Parameter Set Comparison

Parameter Set	Security Level	Public Key	Secret Key	Signature Size	Best for
ML-DSA-44	128-bit	1312 bytes	2560 bytes	2420 bytes	Bandwidth-constrained, IoT
ML-DSA-65	192-bit	1952 bytes	4032 bytes	3309 bytes	General-purpose (recommended)
ML-DSA-87	256-bit	2592 bytes	4896 bytes	4627 bytes	Top-secret-grade, maximum security

Code Examples

Generate ML-DSA key pair and sign with @noble/post-quantum:

// Browser — ML-DSA-65 sign & verify
import { mldsa65 } from '@noble/post-quantum/ml-dsa.js';

// Generate key pair
const seed = crypto.getRandomValues(new Uint8Array(32));
const { publicKey, secretKey } = mldsa65.keygen(seed);

// Sign
const message = new TextEncoder().encode('message to sign');
const signature = mldsa65.sign(secretKey, message);

// Verify
const isValid = mldsa65.verify(publicKey, message, signature);
console.log('Signature valid:', isValid);
console.log('Public key size:', publicKey.length, 'bytes');  // 1952
console.log('Signature size:', signature.length, 'bytes');   // 3309

# Python — ML-DSA-65 with pqcrystals
from pqcrystals.ml_dsa.ref.ml_dsa65 import keygen, sign, verify

# Generate key pair
public_key, secret_key = keygen()

# Sign
message = b"message to sign"
signature = sign(secret_key, message)

# Verify
is_valid = verify(public_key, message, signature)
print(f"Signature valid: {is_valid}")

Security Notes

• All computation stays local — key generation and signing run via audited pure-JS code; no key material ever leaves the browser.
• ML-DSA signing is randomized — signing the same message twice produces different signatures; this is by design and does not affect verification.
• Use FIPS 204 validated implementations for production — this tool is designed for education and prototyping; integrate through a validated library for real deployments.
• Never reuse signing keys across protocols — derive protocol-specific keys with HKDF or a similar KDF before use.
• Account for larger key and signature sizes — ML-DSA-65 uses 1.9 KB public keys and 3.3 KB signatures; ensure your network and storage can handle the bandwidth.

Related Tools

Need classical signatures instead? Try the Ed25519 Sign/Verify tool for fast, compact signatures. For post-quantum key encapsulation, see the ML-KEM Key Encapsulation tool. You can also generate classical key pairs with the RSA Key Generator.