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Bitcoin Address Types

Bitcoin addresses are human-readable encodings of scriptPubKeys — the spending conditions that lock bitcoin to a specific key or set of keys. Over time, address formats have evolved to improve efficiency, privacy, and compatibility.

P2PK — Pay to Public Key (Legacy)​

  • The earliest address format; used in Satoshi-era coinbase transactions
  • Simply locks funds to a public key directly
  • Rare today — privacy leak (public key is visible before spending); replaced by P2PKH

P2PKH — Pay to Public Key Hash (Legacy)​

  • Prefix: 1 (mainnet)
  • Locks funds to the hash of a public key rather than the key itself
  • Requires the spender to reveal the public key and provide a valid signature
  • Still widely used but less efficient than newer formats

P2SH — Pay to Script Hash​

  • Prefix: 3 (mainnet)
  • Locks funds to the hash of an arbitrary script (not just a public key)
  • Enables multisig, timelocks, and more complex spending conditions
  • The full script (redeem script) is only revealed at spend time, improving privacy slightly

Segwit (P2SH-P2WPKH / P2WPKH / Bech32)​

  • Prefixes: bc1q (Bech32 / native Segwit), or nested in 3 addresses
  • Separates witness data (signatures) from the transaction body
  • Benefits:
    • Fixes transaction malleability (critical for Lightning Network)
    • Reduces transaction weight → lower fees
    • Larger effective block capacity without changing the 1MB block size

Taproot (P2TR / Bech32m)​

  • Prefix: bc1p
  • Activated via soft fork in November 2021
  • Combines single-sig and multisig into a single public key appearance on-chain
  • Enables Merklized Alternative Script Trees (MAST) — only the executed script branch is revealed
  • Improves privacy by making multisig and complex scripts look identical to single-sig
  • Sets the stage for Schnorr signatures (BATCH verification, signature aggregation)

Comparison​

TypePrefixEfficiencyPrivacyUse Case
P2PK—LowPoorHistorical only
P2PKH1MediumBasicGeneral wallets
P2SH3MediumBasicMultisig, legacy scripts
P2WPKHbc1qHighBasicModern single-sig
P2TRbc1pHighestBestModern wallets, multisig, scripts

Resources​