Getting Addresses using a Path causes the error: Could not derive hardened child key

Question

I am using ethereumjs-wallet npm package to generate a unique wallet address for each user. However instead of using the mnemonic/seed, a public extended key xpub will be used instead to keep the private keys secure.

However the following code which I used is throwing the error

AssertionError [ERR_ASSERTION]: Could not derive hardened child key

The code works fine if we were to replace

const hdWallet = hdkey.fromExtendedKey("xpub...")

with

const hdWallet = hdkey.fromSeed("seed or mnemonic ...")

It appears to be a problem with the hdPath, but which exactly is the problem? And how can we solve it?

JS Code

var hdkey = require('ethereumjs-wallet/hdkey')

const hdWallet = hdkey.fromExtendedKey("xpub...")
const hdPath  = "m/44'/60'/0'/1/0"
const node = hdWallet.derivePath(hdPath)
const nodeWallet = node.getWallet()
const address = nodeWallet.getAddressString()
return address

Answer 1

I know its not exactly what you're after, but you can derive form non hardened:

var hdkey = require('ethereumjs-wallet/hdkey')

const hdWallet = hdkey.fromExtendedKey("xpub6Cy7dUR4ZKF22HEuVq7epRgRsoXfL2MK1RE81CSvp1ZySySoYGXk5PUY9y9Cc5ExpnSwXyimQAsVhyyPDNDrfj4xjDsKZJNYgsHXoEPNCYQ")
const hdPath  = "m/44/60/0/1/0"
const node = hdWallet.derivePath(hdPath)
const nodeWallet = node.getWallet()
const address = nodeWallet.getAddressString()
console.log(address)