Wallet Backup Formats BIP39 mnemonic (standard) 12 / 15 / 18 / 21 / 24 words from BIP39 wordlist + optional passphrase. Recoverable into any BIP39-compatible wallet. Encoding density: 12 words ≈ 132 bits (128 entropy + 4 checksum). Average length: 70-90 ASCII chars. SLIP-39 Shamir Backup Trezor-introduced format using Shamir's Secret Sharing: - M-of-N share threshold. - Each share is 20-33 words from a different wordlist (1024 words). - Can be split into groups (e.g., 2-of-3 family + 2-of-2 board) for hierarchical recovery. Use case: distributing shares geographically/socially without giving…