Bip39 Checksum. Now, at the next stage we use these receiving and alter essential bunch to crank out person personal keys. Use the above mentioned make private keys and chain code and move them to the above mentioned function kchild = kpar + hash(Kpar, cpar, i) to deliver personal keys. https://kingslists.com/story20304114/bip39-https-linktr-ee-bip39-bip-39-no-further-a-mystery