Bip39 Ian Coleman. Now, at the next degree we use these getting and change key bunch to generate personal private keys. Use the above make personal keys and chain code and go them to the above mentioned stated purpose kchild = kpar + hash(Kpar, cpar, i) to make personal keys. https://thebookmarkplaza.com/story19501135/bip39-passphrase-https-linktr-ee-bip39-helping-the-others-realize-the-advantages-of-bip39