mirror of
https://github.com/bitcoin/bips.git
synced 2024-11-19 18:00:08 +01:00
252 lines
6.3 KiB
Plaintext
252 lines
6.3 KiB
Plaintext
<pre>
|
||
BIP: 48
|
||
Layer: Applications
|
||
Title: Multi-Script Hierarchy for Multi-Sig Wallets
|
||
Author: Fontaine <dentondevelopment@protonmail.com>
|
||
Comments-Summary: No comments
|
||
Comments-URI: https://github.com/bitcoin/bips/wiki/Comments:BIP-0048
|
||
Status: Proposed
|
||
Type: Standards Track
|
||
Created: 2020-12-16
|
||
License: MIT
|
||
</pre>
|
||
|
||
==Abstract==
|
||
|
||
This BIP defines a logical hierarchy for deterministic multi-sig wallets based on an algorithm
|
||
described in BIP-0067 (BIP67 from now on), BIP-0032 (BIP32 from now on), purpose scheme described in
|
||
BIP-0043 (BIP43 from now on), and multi-account hierarchy described in
|
||
BIP-0044 (BIP44 from now on).
|
||
|
||
This BIP is a particular application of BIP43.
|
||
|
||
==Copyright==
|
||
|
||
This BIP falls under the MIT License.
|
||
|
||
==Motivation==
|
||
|
||
The motivation of this BIP is to define the existing industry wide practice of utilizing m/48'
|
||
derivation paths in hierarchical deterministic multi-sig wallets so that other developers may
|
||
benefit from a standard. This BIP allows for future script types to easily be appended to the
|
||
specification so that a new BIP is not required for every future script type.
|
||
|
||
The hierarchy proposed in this paper is quite comprehensive. It allows the handling of
|
||
multiple accounts, external and internal chains per account, multiple script types and
|
||
millions of addresses per chain.
|
||
|
||
This paper was inspired from BIP44.
|
||
|
||
==Backwards compatibility==
|
||
|
||
Currently a number of wallets utilize the <code>m/48'</code> derivation scheme for HD multi-sig accounts.
|
||
This BIP is intended to maintain the *existing* real world use of the <code>m/48'</code> derivation.
|
||
No breaking changes are made so as to avoid "loss of funds" to existing users.
|
||
Wallets which currently support the <code>m/48'</code> derivation will not need to make any changes
|
||
to comply with this BIP.
|
||
|
||
==Specification==
|
||
|
||
===Key sorting===
|
||
|
||
Any wallet that supports BIP48 inherently supports deterministic key sorting as per BIP67 so that all possible
|
||
multi-signature addresses/scripts are derived from deterministically sorted public keys.
|
||
|
||
===Path levels===
|
||
|
||
We define the following 6 levels in BIP32 path:
|
||
|
||
<pre>
|
||
m / purpose' / coin_type' / account' / script_type' / change / address_index
|
||
</pre>
|
||
|
||
<code>h</code> or <code>'</code> in the path indicates that BIP32 hardened derivation is used.
|
||
|
||
Each level has a special meaning, described in the chapters below.
|
||
|
||
===Purpose===
|
||
|
||
Purpose is a constant set to 48' following the BIP43 recommendation.
|
||
It indicates that the subtree of this node is used according to this specification.
|
||
|
||
Hardened derivation is used at this level.
|
||
|
||
===Coin type===
|
||
|
||
One master node (seed) can be used for multiple Bitcoin networks.
|
||
Sharing the same space for various networks has some disadvantages.
|
||
|
||
Avoiding reusing addresses across networks and improving privacy issues.
|
||
|
||
Coin type <code>0</code> for mainnet and <code>1</code> for testnet.
|
||
|
||
Hardened derivation is used at this level.
|
||
|
||
===Account===
|
||
|
||
This level splits the key space into independent user identities, following the BIP44 pattern,
|
||
so the wallet never mixes the coins across different accounts.
|
||
|
||
Users can use these accounts to organize the funds in the same
|
||
fashion as bank accounts; for donation purposes (where all
|
||
addresses are considered public), for saving purposes,
|
||
for common expenses etc.
|
||
|
||
Accounts are numbered from index 0 in sequentially increasing manner.
|
||
This number is used as child index in BIP32 derivation.
|
||
|
||
Hardened derivation is used at this level.
|
||
|
||
===Script===
|
||
|
||
This level splits the key space into two separate <code>script_type</code>(s). To provide
|
||
forward compatibility for future script types this specification can be easily extended.
|
||
|
||
Currently the only script types covered by this BIP are Native Segwit (p2wsh) and
|
||
Nested Segwit (p2sh-p2wsh).
|
||
|
||
The following path represents Nested Segwit (p2sh-p2wsh) mainnet, account 0:
|
||
<code>1'</code>: Nested Segwit (p2sh-p2wsh) <code>m/48'/0'/0'/1'</code></br>
|
||
|
||
The following path represents Native Segwit (p2wsh) mainnet, account 0:
|
||
<code>2'</code>: Native Segwit (p2wsh) <code>m/48'/0'/0'/2'</code></br>
|
||
|
||
The recommended default for wallets is pay to witness script hash <code>m/48'/0'/0'/2'</code>.
|
||
|
||
To add new script types submit a PR to this specification and include it in the list above:
|
||
<code>X'</code>: Future script type <code>m/48'/0'/0'/X'</code></br>
|
||
|
||
===Change===
|
||
|
||
Constant 0 is used for external chain and constant 1 for internal chain (also
|
||
known as change addresses). External chain is used for addresses that are meant
|
||
to be visible outside of the wallet (e.g. for receiving payments). Internal
|
||
chain is used for addresses which are not meant to be visible outside of the
|
||
wallet and is used for return transaction change.
|
||
|
||
Public derivation is used at this level.
|
||
|
||
===Index===
|
||
|
||
Addresses are numbered from index 0 in sequentially increasing manner.
|
||
This number is used as child index in BIP32 derivation.
|
||
|
||
Public derivation is used at this level.
|
||
|
||
==Examples==
|
||
|
||
{|
|
||
|network
|
||
|account
|
||
|script
|
||
|chain
|
||
|address
|
||
|path
|
||
|-
|
||
|mainnet
|
||
|first
|
||
|p2wsh
|
||
|external
|
||
|first
|
||
|m / 48' / 0' / 0' / 2' / 0 / 0
|
||
|-
|
||
|mainnet
|
||
|first
|
||
|p2wsh
|
||
|external
|
||
|second
|
||
|m / 48' / 0' / 0' / 2' / 0 / 1
|
||
|-
|
||
|mainnet
|
||
|first
|
||
|p2wsh
|
||
|change
|
||
|first
|
||
|m / 48' / 0' / 0' / 2' / 1 / 0
|
||
|-
|
||
|mainnet
|
||
|first
|
||
|p2wsh
|
||
|change
|
||
|second
|
||
|m / 48' / 0' / 0' / 2' / 1 / 1
|
||
|-
|
||
|mainnet
|
||
|second
|
||
|p2wsh
|
||
|external
|
||
|first
|
||
|m / 48' / 0' / 1' / 2' / 0 / 0
|
||
|-
|
||
|mainnet
|
||
|second
|
||
|p2wsh
|
||
|external
|
||
|second
|
||
|m / 48' / 0' / 1' / 2' / 0 / 1
|
||
|-
|
||
|testnet
|
||
|first
|
||
|p2sh-p2wsh
|
||
|external
|
||
|first
|
||
|m / 48' / 1' / 0' / 1' / 0 / 0
|
||
|-
|
||
|testnet
|
||
|first
|
||
|p2wsh
|
||
|external
|
||
|second
|
||
|m / 48' / 1' / 0' / 2' / 0 / 1
|
||
|-
|
||
|testnet
|
||
|first
|
||
|p2wsh
|
||
|change
|
||
|first
|
||
|m / 48' / 1' / 0' / 2' / 1 / 0
|
||
|-
|
||
|testnet
|
||
|first
|
||
|p2wsh
|
||
|change
|
||
|second
|
||
|m / 48' / 1' / 0' / 2' / 1 / 1
|
||
|-
|
||
|testnet
|
||
|second
|
||
|p2wsh
|
||
|external
|
||
|first
|
||
|m / 48' / 1' / 1' / 2' / 0 / 0
|
||
|-
|
||
|testnet
|
||
|second
|
||
|p2wsh
|
||
|external
|
||
|second
|
||
|m / 48' / 1' / 1' / 2' / 0 / 1
|
||
|-
|
||
|testnet
|
||
|second
|
||
|p2wsh
|
||
|change
|
||
|first
|
||
|m / 48' / 1' / 1' / 2' / 1 / 0
|
||
|-
|
||
|testnet
|
||
|second
|
||
|p2wsh
|
||
|change
|
||
|second
|
||
|m / 48' / 1' / 1' / 2' / 1 / 1
|
||
|}
|
||
|
||
|
||
==Reference==
|
||
|
||
* [[bip-0067.mediawiki|BIP67 - Deterministic Pay-to-script-hash multi-signature addresses through public key sorting]]
|
||
* [[bip-0032.mediawiki|BIP32 - Hierarchical Deterministic Wallets]]
|
||
* [[bip-0043.mediawiki|BIP43 - Purpose Field for Deterministic Wallets]]
|
||
* [[bip-0044.mediawiki|BIP44 - Multi-Account Hierarchy for Deterministic Wallets]]
|