BIP-39

• BIP-39 bitcoin improvement proposal to make human-readable mnemonic phrase for random entropy

  • BIP-39 (Bitcoin Improvement Proposal 39) is a standard for encoding random entropy into a human-readable mnemonic phrase—typically used to back up and recover cryptocurrency wallets.

  • Core idea

    • It converts a binary seed (random bits) into a sequence of common English words like:

    • abandon ability able about above absent absorb abstract absurd abuse access accident

    • This phrase can later be converted back into the exact same seed.

  • How it works (simplified)

    • Generate entropy
      • 128–256 bits of randomness
    • Add checksum
      • A few bits derived from a hash of the entropy
    • Split into chunks
      • Each chunk is 11 bits
    • Map to words
      • Each 11-bit value indexes into a fixed list of 2048 words

  • Key properties

    • Deterministic
      • Same phrase → same seed → same wallet
    • Word list (2048 words)
      • Carefully designed:
        • No ambiguous words
        • No homophones
        • First 4 letters uniquely identify each word
    • Error resistance
      • Checksum helps detect mistakes
    • Human-friendly
      • Easier to write down, say aloud, and remember than hex strings

  • Typical sizes

    • Words	Entropy
      12	128-bit
      15	160-bit
      18	192-bit
      21	224-bit
      24	256-bit

  • Where it's used

    • Bitcoin, Ethereum, and most crypto wallets
    • Hardware wallets (Ledger, Trezor)
    • Any system needing portable, human-readable secrets

  • Why it shows up in that GitHub issue

    • The proposal is repurposing BIP-39 for ID generation:
    • Instead of: bd-x7q
    • Use: bd-calm-fox
    • Because the word list is:
      • easy to dictate
      • easy to remember
      • globally standardized
      • already optimized for human communication

  • Important distinction

    • BIP-39 is:
      • not encryption
      • not a wallet format itself
    • It's just a mapping layer:

    • entropy ↔ mnemonic words ↔ seed (via PBKDF2)