BIP 0084

BIP: 84
 Layer: Applications
 Title: Derivation scheme for P2WPKH based accounts
 Author: Pavol Rusnak <stick@satoshilabs.com>
 Comments-Summary: No comments yet.
 Comments-URI: https://github.com/bitcoin/bips/wiki/Comments:BIP-0084
 Status: Final
 Type: Standards Track
 Created: 2017-12-28
 License: CC0-1.0
==Abstract==
This BIP defines the derivation scheme for HD wallets using the P2WPKH (BIP 173) serialization format for segregated witness transactions.
==Motivation==
With the usage of P2WPKH transactions it is necessary to have a common derivation scheme.
It allows the user to use different HD wallets with the same masterseed and/or a single account seamlessly.
Thus the user needs to create dedicated segregated witness accounts, which ensures that only wallets compatible with this BIP will detect the accounts and handle them appropriately.
===Considerations===
We use the same rationale as described in Considerations section of BIP 49.
==Specifications==
This BIP defines the two needed steps to derive multiple deterministic addresses based on a BIP 32 root account.
===Public key derivation===
To derive a public key from the root account, this BIP uses the same account-structure as defined in BIP 44 and BIP 49, but only uses a different purpose value to indicate the different transaction serialization method.
m / purpose' / coin_type' / account' / change / address_index
For the purpose-path level it uses 84'. The rest of the levels are used as defined in BIP44 or BIP49.
===Address derivation===
To derive the P2WPKH address from the above calculated public key, we use the encapsulation defined in BIP 141:
 witness: <signature> <pubkey>
 scriptSig: (empty)
 scriptPubKey: 0 <20-byte-key-hash>
 (0x0014{20-byte-key-hash})
===Extended Key Version===
When serializing extended keys, this scheme uses alternate version bytes. Extended public keys use 0x04b24746 to produce a "zpub" prefix, and private keys use 0x04b2430c to produce a "zprv" prefix. Testnet uses 0x045f1cf6 "vpub" and 0x045f18bc "vprv."
Additional registered version bytes are listed in [].
==Backwards Compatibility==
This BIP is not backwards compatible by design as described under [#considerations]. An incompatible wallet will not discover accounts at all and the user will notice that something is wrong.
==Test vectors==
 mnemonic = abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon about
 rootpriv = zprvAWgYBBk7JR8Gjrh4UJQ2uJdG1r3WNRRfURiABBE3RvMXYSrRJL62XuezvGdPvG6GFBZduosCc1YP5wixPox7zhZLfiUm8aunE96BBa4Kei5
 rootpub = zpub6jftahH18ngZxLmXaKw3GSZzZsszmt9WqedkyZdezFtWRFBZqsQH5hyUmb4pCEeZGmVfQuP5bedXTB8is6fTv19U1GQRyQUKQGUTzyHACMF
 // Account 0, root = m/84'/0'/0'
 xpriv = zprvAdG4iTXWBoARxkkzNpNh8r6Qag3irQB8PzEMkAFeTRXxHpbF9z4QgEvBRmfvqWvGp42t42nvgGpNgYSJA9iefm1yYNZKEm7z6qUWCroSQnE
 xpub = zpub6rFR7y4Q2AijBEqTUquhVz398htDFrtymD9xYYfG1m4wAcvPhXNfE3EfH1r1ADqtfSdVCToUG868RvUUkgDKf31mGDtKsAYz2oz2AGutZYs
 // Account 0, first receiving address = m/84'/0'/0'/0/0
 privkey = KyZpNDKnfs94vbrwhJneDi77V6jF64PWPF8x5cdJb8ifgg2DUc9d
 pubkey = 0330d54fd0dd420a6e5f8d3624f5f3482cae350f79d5f0753bf5beef9c2d91af3c
 address = bc1qcr8te4kr609gcawutmrza0j4xv80jy8z306fyu
 // Account 0, second receiving address = m/84'/0'/0'/0/1
 privkey = Kxpf5b8p3qX56DKEe5NqWbNUP9MnqoRFzZwHRtsFqhzuvUJsYZCy
 pubkey = 03e775fd51f0dfb8cd865d9ff1cca2a158cf651fe997fdc9fee9c1d3b5e995ea77
 address = bc1qnjg0jd8228aq7egyzacy8cys3knf9xvrerkf9g
 // Account 0, first change address = m/84'/0'/0'/1/0
 privkey = KxuoxufJL5csa1Wieb2kp29VNdn92Us8CoaUG3aGtPtcF3AzeXvF
 pubkey = 03025324888e429ab8e3dbaf1f7802648b9cd01e9b418485c5fa4c1b9b5700e1a6
 address = bc1q8c6fshw2dlwun7ekn9qwf37cu2rn755upcp6el
==Reference==
* BIP32 - Hierarchical Deterministic Wallets
* BIP43 - Purpose Field for Deterministic Wallets
* BIP44 - Multi-Account Hierarchy for Deterministic Wallets
* BIP49 - Derivation scheme for P2WPKH-nested-in-P2SH based accounts
* BIP141 - Segregated Witness (Consensus layer)
* BIP173 - Base32 address format for native v0-16 witness outputs