Bip39. The passphrase isn't chosen with the predefined list of 2048 words – it may be any word or phrase you choose. BIP39 specifies a list of 2048 words from which the mnemonic phrase is picked out. Each word signifies a number inside a binary sequence, plus the phrase is https://pageoftoday.com/story4603259/bip39-wallets-https-linktr-ee-bip39-a-review-of-bip39-generator