Bip39 Checksum. Is passphrase similar to PIN? No, a passphrase is just not the same as a PIN. A passphrase, while in the context of Bitcoin wallets, is an extra layer of safety in your wallet that actually works together with your seed phrase to encrypt and defend your wallet. https://thejillist.com/story8777771/bip39-passphrase-https-linktr-ee-bip39-not-known-factual-statements-about-ian-coleman-bip39