Bip39. Moreover, BIP39 defines the passphrase option, that adds a reasonable number of additive security in case your seed phrase is stolen or in any other case accidentally uncovered. On the other hand, What's more, it adds some risk, so it is suggested for more experienced customers. BIP39 Passphrase Wallet https://directory-url.com/listings13100093/bip39-list-https-linktr-ee-bip39-rumored-buzz-on-bip39-standard