As you have seen, generating HD keys is easy. However, what if we want an easy way to transmit such a key by telephone or hand writing?
Cold wallets like Trezor, generate the HD Keys from a sentence that can easily be written down. They call such a sentence “the seed” or “mnemonic”. And it can eventually be protected by a password or a PIN.
The language that you use to generate your 'easy to write' sentence is called a Wordlist.
Mnemonic mnemo = new Mnemonic(Wordlist.English, WordCount.Twelve);ExtKey hdRoot = mnemo.DeriveExtKey("my password");Console.WriteLine(mnemo);
minute put grant neglect anxiety case globe win famous correct turn link
Now, if you have the mnemonic and the password, you can recover the hdRoot key.
mnemo = new Mnemonic("minute put grant neglect anxiety case globe win famous correct turn link",Wordlist.English);hdRoot = mnemo.DeriveExtKey("my password");
Currently supported languages for wordlist are, English, Japanese, Spanish, Chinese (simplified and traditional).