Public Addresses

As it usually happens in Blockchain, public addresses are derived from a public key by hashing it. In the Stardust protocol, they are derived from the Ed25519 public key.

There are two different address formats:

• Ed25519: A hash of the Ed25519 public key.

• Bech32: An easily identified and error-resistant format that complies with BECH32.

  In the case of the Shimmer mainnet, the BECH32 human-readable part (HRP) is smr, and rms is used for the Shimmer testnet. Those HRPs are also provided as metadata elements of the info primitive of the protocol.

const publicAddresses: { ed25519: string; bech32: string }[] = [];

for (const keyPair of keyPairs) {
  const ed25519Address = new Ed25519Address(keyPair.publicKey);
  // Address in bytes
  const ed25519AddressBytes = ed25519Address.toAddress();
  // Conversion to BECH32
  const bech32Addr = Bech32Helper.toBech32(
    ED25519_ADDRESS_TYPE,
    ed25519AddressBytes,
    'rms',
  );

  const publicAddress = {
    ed25519: Converter.bytesToHex(ed25519AddressBytes, true),
    bech32: bech32Addr,
  };
  publicAddresses.push(publicAddress);

  console.log(publicAddress);
}

As you can see, the BECH32 address is generated from the Ed25519 address, which it is a hash of the public key.

This results in the following:

{
  ed25519: '0x1696e3735e8871ce7086af6a9920e1a3b83cdf8b265adf449fc4bda86b91e2bb',
  bech32: 'rms1qqtfdcmnt6y8rnnss6hk4xfqux3ms0xl3vn94h6ynlztm2rtj83tk9qkzrx'
}

The Ed25519 format has a length of 64 hex chars (32 bytes) as the Ed25519 public key. On the other hand, the BECH32 address starts with rms or smr and continues with a 1 character.

You can now transform the BECH32 address into an Ed25519 address using the Bech32Helper.fromBech32() function, as shown in the following snippet:

const ed25519Addr = Bech32Helper.fromBech32(bech32Address, 'rms').addressBytes;

However, you cannot derive your Ed25519 public key, as it is a hash of a public key, and hashes are irreversible functions.

Putting It All Together

By this point in the tutorial, your generate-addresses.ts file should look something like this:

import { Bip32Path, Bip39 } from '@iota/crypto.js';
import {
  Bech32Helper,
  ED25519_ADDRESS_TYPE,
  Ed25519Address,
  Ed25519Seed,
  generateBip44Address,
  IKeyPair,
} from '@iota/iota.js';
import { Converter } from '@iota/util.js';

// Default entropy length is 256
const randomMnemonic = Bip39.randomMnemonic();

console.log('Seed phrase:', randomMnemonic);

const masterSeed = Ed25519Seed.fromMnemonic(randomMnemonic);

const NUM_ADDR = 6;
const addressGeneratorAccountState = {
  accountIndex: 0,
  addressIndex: 0,
  isInternal: false,
};
const paths: string[] = [];
for (let i = 0; i < NUM_ADDR; i++) {
  const path = generateBip44Address(addressGeneratorAccountState);
  paths.push(path);

  console.log(`${path}`);
}

const keyPairs: IKeyPair[] = [];

for (const path of paths) {
  // Master seed was generated previously
  const addressSeed = masterSeed.generateSeedFromPath(new Bip32Path(path));
  const addressKeyPair = addressSeed.keyPair();
  keyPairs.push(addressKeyPair);

  console.log(Converter.bytesToHex(addressKeyPair.privateKey, true));
  console.log(Converter.bytesToHex(addressKeyPair.publicKey, true));
}

const publicAddresses: { ed25519: string; bech32: string }[] = [];

for (const keyPair of keyPairs) {
  const ed25519Address = new Ed25519Address(keyPair.publicKey);
  // Address in bytes
  const ed25519AddressBytes = ed25519Address.toAddress();
  // Conversion to BECH32
  const bech32Addr = Bech32Helper.toBech32(
    ED25519_ADDRESS_TYPE,
    ed25519AddressBytes,
    'rms',
  );

  const publicAddress = {
    ed25519: Converter.bytesToHex(ed25519AddressBytes, true),
    bech32: bech32Addr,
  };
  publicAddresses.push(publicAddress);

  console.log(publicAddress);
}