Key Hardening (pqcHardened)

FLASH can harden a passphrase with scrypt → SHA3-256 before AES key use (pqcHardened: true).

This is not NIST ML-KEM / Kyber. Key agreement in FlashPQC uses ECDH on secp256k1 plus SHA3-256. Treat it as extra passphrase stretching and classical ECDH — not post-quantum confidentiality.

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Enabling hardened key expansion

import { FlashClient } from "flash-zk";

const client = new FlashClient({
  storagePath: "./flash_data",
  pqcHardened: true,
});

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ECDH helpers (FlashPQC)

import { FlashPQC } from "flash-zk";

const aliceKeys = FlashPQC.generateKeyPair();
const { sharedSecret, ciphertext } = FlashPQC.encapsulateSecret(
  aliceKeys.publicKey,
);
const decryptedSecret = FlashPQC.decapsulateSecret(
  ciphertext,
  aliceKeys.secretKey,
);

console.log("Secrets match:", sharedSecret.equals(decryptedSecret));