It's not needed to know all the details of BIP39 in an effort to use copyright - but you would definitely reap the benefits of being aware of a little about this. The best way to retrieve extended personal crucial from extended community crucial + learn seed / root non-public http://jaspermuxp089.yousher.com/from-mnemonics-to-security-comprehending-bip39-passphrases-and-their-significance-in-copyright