Bip39 Checksum. Now, at the next stage we use these acquiring and change key bunch to crank out specific personal keys. Use the above crank out private keys and chain code and go them to the above described purpose kchild = kpar + hash(Kpar, cpar, i) to deliver person keys. https://singnalsocial.com/story4487386/bip39-list-https-linktr-ee-bip39-a-simple-key-for-bip39-unveiled