Mnemonic

Implements SEP-0005 Key Derivation Methods for Stellar Keys.

Provides hierarchical deterministic key derivation from BIP-39 mnemonic phrases using the Stellar-specific derivation path m/44'/148'/x' where:

• 44' is the BIP-44 purpose (hardened)

• 148' is the Stellar coin type from SLIP-0044 (hardened)

• x' is the account index (hardened)

The mnemonic supports:

• BIP-39 mnemonic generation in 9 languages (English, Chinese Simplified, Chinese Traditional, French, Italian, Japanese, Korean, Spanish, Malay)

• All BIP-39 word lengths: 12, 15, 18, 21, and 24 words

• Mnemonic validation with checksum verification

• SLIP-0010 hierarchical deterministic key derivation for Ed25519

• Optional BIP-39 passphrase for additional security

Usage Example

// Generate a 24-word mnemonic (recommended)
val mnemonic = Mnemonic.generate24WordsMnemonic()

// Create Mnemonic instance from phrase
val mnemonic = Mnemonic.from(mnemonic)

// Derive keypairs for multiple accounts
val account0 = mnemonic.getKeyPair(index = 0)
val account1 = mnemonic.getKeyPair(index = 1)

// Get account ID only (more efficient for display)
val accountId = mnemonic.getAccountId(index = 0)

// With passphrase for additional security
val secureMnemonic = Mnemonic.from(mnemonic, passphrase = "my secret passphrase")

// Clean up when done
mnemonic.close()

Security Considerations

• Store mnemonics securely: Never expose mnemonics in logs, error messages, or insecure storage

• Never log sensitive data: Mnemonics, BIP-39 seeds, and private keys must never be logged

• Use close(): Call close when the mnemonic instance is no longer needed to zero internal seed data

• Passphrase handling: Lost passphrases cannot be recovered; the mnemonic alone cannot restore access to funds if a passphrase was used

• Validate mnemonics: Always validate mnemonics before use with validate

Implementation Details

Key derivation follows SLIP-0010 for Ed25519:

1. Master key: HMAC-SHA512(key = "ed25519 seed", data = BIP39_seed)

2. Child derivation: HMAC-SHA512(key = parent_chain_code, data = 0x00 || parent_key || index + 2^31)

All derivation is hardened (indicated by apostrophe in path) as required by Ed25519.

See also