BIP-39: Mnemonic Code for Generating Deterministic Keys
Seed phrases are the primary backup mechanism for all HD wallets. BIP-39 defines the 12/24 word format, wordlist, and checksum — everything about the backup experience.
What It Defines
Defines the mnemonic (seed phrase) standard: 12/24 English words from a 2048-word wordlist encoding a 128/256-bit entropy value + checksum. The seed phrase maps to a BIP-32 master seed.
Canonical (Normative)
Related References
The Bitcoin community's open process for proposing protocol changes, standards, and informational documents. BIPs cover everything from consensus rules to wallet derivation paths and payment URIs.
Related Specs
Every modern cryptocurrency wallet (Ledger, Trezor, MetaMask, Coinbase Wallet) uses BIP-32 for key derivation. The foundation of the seed phrase model.
Derivation paths determine which addresses you get from a seed phrase on each chain. BIP-44 paths (m/44'/60'/0'/0/0 for ETH) explain why the same seed gives different addresses on different wallets.