React Native: Solutions for slow crypto-operations (`Wallet.createRandom()`)

A lot of issues have been opened about React Native being slow. For example, creating a wallet takes 33 seconds on an iPhone 11 Pro - I don’t even want to find out how slow that is on an older Android device.

This code:

import 'react-native-get-random-values'
import '@ethersproject/shims'
import { ethers } from 'ethers'


  const now = performance.now()
  Logger.log('💰 Creating new Wallet...')
  const wallet = ethers.Wallet.createRandom()
  const end = performance.now()
  Logger.log(
    `💰 New wallet created! Took ${end - now}ms, Phrase: ${wallet.mnemonic.phrase}`,
  )

Takes half a minute:

[16:49:19.253]	💰 Creating new Wallet...
[16:49:52.812]	💰 New wallet created! Took 33559.440958321095ms, Phrase: ...

See https://github.com/facebook/hermes/issues/626

I’m wondering if there is any workaround to make this code faster, as it’s definitely not a solution to let the user wait for 5 minutes until he can use the app.

I can create a library for the crypto polyfills that uses a pure C/C++ implementation accessed synchronously through JSI for maximum performance, but I’d need help to find out what algorithms are slow and where I can swap them.

[mrousavy]

Do you have an ETA for v6?

[mrousavy]

I did it.

@zemse @mirceanis @ricmoo how do I swap the pbkdf2 function?

The one from this library takes 14 seconds:

ether's pbkdf2 took 14279.91887497902ms

and my pure C++ JSI implementation takes 0.001 second:

C++ pbkdf2 took 1.4742500185966492ms

…so it’s almost 10.000x faster.

I’d love to make that open source if there’s a way to swap the implementations.