How to programmatically generate sub addresses using the root address in hd wallet?

Question

And without using the private key. I've been digging into the ConsenSys's eth-lightwallet, although it uses a derived private key to generate the address which would expose the root private in danger.

Thanks!

Answer 1

You can generate new addresses with extended public key, but you'll have access to them just with your extended private key. In bip32 standard there is an explanation of how the process is going. Also you can read bip44 for better understanding of process.

Answer 2

https://github.com/ethereumjs/ethereumjs-wallet you can use fromExtendedKey method of 'ethereumjs-wallet/hdkey'