Ways to securely generate private key

[emclab]

I current use ethers.Wallet.createRandom() to generate private key by extracting .privateKey in React Native 0.64 app. What is other way to securely generate private key? The ethersjs version is 5.3.0.

[ricmoo]

If you only need a private key, you can just use utils.randomBytes(32).

The Wallet.createRandom method uses 16 bytes of random data to create a random 12-word mnemonic, and then uses Wallet.fromMnemonic, so random wallets will have an associated mnemonic.

[ricmoo]

(this is assuming you have correctly installed a secure random source in your react native app)

[emclab]

yes, I do have the secure random source in RN app. It is the react-native-secure-random-values which is recommended in the doc.

[emclab]

I will eventually need the wallet as well. What I found is that ethers.Wallet.createRandom() is extremely slow and at the end throws error of unhandled promise. But new ethers.Wallet(privateKey); is fast. I tested both Wallet.createRandom and Wallet(privateKey) with a one page RN app. I am not sure where goes wrong here. Here is the test code (RN 0.64):

import 'react-native-get-random-values';
import "@ethersproject/shims";  //for ethers.js
// Import the ethers library
import { ContractFactory, ethers } from "ethers";

export default App() {
useEffect(() => {

    const asyncFn =  async() => {
      try{
        let _wallet = ethers.Wallet.createRandom(); >>//<<==extremely slow. seems never ends.
        console.log("private key ", _wallet.privateKey); 

      } catch(err) {
  
      }
  
    }
    asyncFn();
  }, []);

[emclab]

Here is the discussion post about the Wallet.createRandom(). All ethers is 5.3.0 which is up to date.

#1645

[emclab]

I am wondering if there is any security difference between private keys created from ethers.utils.randomBytes(32) and ethers.Wallet.createRandom().privateKey. My understanding is that they shall be equally secure.