Key generation

The minimal JavaScript code used to generate a private key from Passphrase and PIN inputs is shown below.

import { Buffer } from "buffer";
import { ethers } from "ethers";
import { scrypt } from "scrypt-js";

const HASH_OPTIONS = {
  N: 131072, // CPU/memory cost parameter, 2^17
  r: 8, // block size parameter
  p: 1, // parallelization parameter
  keyLen: 64,
};
const KDF_DOMAIN_SEPARATOR = "mybucks.online-core.generateHash.v2";

async function generatePrivateKey(passphrase, pin) {
  const passwordBuffer = Buffer.from(passphrase);
  const encoded = abi.encode(
    ["string", "string", "string"],
    [KDF_DOMAIN_SEPARATOR, passphrase, pin],
  );
  const saltHash = ethers.keccak256(encoded);
  const saltBuffer = Buffer.from(saltHash.slice(2), "hex");

  const hashBuffer = await scrypt(
    passwordBuffer,
    saltBuffer,
    HASH_OPTIONS.N,
    HASH_OPTIONS.r,
    HASH_OPTIONS.p,
    HASH_OPTIONS.keyLen,
    (p) => console.log(Math.floor(p * 100))
  );
  const hashHex = Buffer.from(hashBuffer).toString("hex");
  const privateKey = ethers.keccak256(abi.encode(["string"], [hashHex]));

  return privateKey;
}

You can find the code here on Github. You can download the repository and execute it on your local machine as a confirmation and backup for account generation.

And the same codebase is encapsulated in the @mybucks.online/core npm package, facilitating developers in integrating wallet generation into third-party platforms or services.

Run in Sandbox

You can also execute this key-generation process in CodeSandbox without setting up a local environment. Please find the interactive CodeSandbox link here.