ethers.js - How to derive child addresses + private keys from HD private key

Question

I have a HD private key which I have derived from my mnemonic using the ethers library. I would now like to derive child addresses and corresponding private keys from it.

Does anybody know how I can do this?

This is how I have obtained the HD private key:

const xKey = ethers.Wallet.fromMnemonic(...)

Thanks in advance!

score 2 · Answer 1 · answered Nov 05 '19 at 00:32

2

const derived = xKey.derivePath("m/44'/60'/0'/0/0");

You should use the derivePath function of the master key, specifying the path of the derived keys.

See more bip-32 and hdnode.

answered Nov 05 '19 at 00:32

Arnaudov_St

137
1
7

FYI to others, this is the typical way we generate derived keys. We can simply increase the index to get more keys. "m/44'/60'/0'/0/n" See https://github.com/ethereum/EIPs/issues/84 for more info. – valem May 26 '20 at 23:16

score 1 · Accepted Answer · answered Oct 22 '19 at 09:02

ethers.Wallet.fromMnemonic is used to create the master private key out of they mnemonic, but for creating new pairs of public and private keys I think you should use this method with different passphrase for each pair:

const HDNode  = await ethers.utils.HDNode.fromMnemonic(YOUR_MNEMONIC, null, YOUR_PASSPHRASE);

When you check the new generated HDNode inside of it you can see it contains the same mnenomic you used for the master private key.

ethers.js - How to derive child addresses + private keys from HD private key

2 Answers2