diff --git a/README.mediawiki b/README.mediawiki index 3db07a28..f3dbcda1 100644 --- a/README.mediawiki +++ b/README.mediawiki @@ -258,6 +258,13 @@ Those proposing changes should consider that ultimately consent may rest with th | Justus Ranvier | Informational | Draft +|- style="background-color: #ffffcf" +| [[bip-0048.mediawiki|48]] +| Applications +| Multi-Script Hierarchy for Multi-Sig Wallets +| Fontaine +| Standard +| Proposed |- style="background-color: #cfffcf" | [[bip-0049.mediawiki|49]] | Applications diff --git a/bip-0048.mediawiki b/bip-0048.mediawiki new file mode 100644 index 00000000..0b099b3f --- /dev/null +++ b/bip-0048.mediawiki @@ -0,0 +1,251 @@ +
+  BIP: 48
+  Layer: Applications
+  Title: Multi-Script Hierarchy for Multi-Sig Wallets
+  Author: Fontaine 
+  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
+
+ +==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 ‎m/48' derivation scheme for HD multi-sig accounts. +This BIP is intended to maintain the *existing* real world use of the ‎m/48' derivation. +No breaking changes are made so as to avoid "loss of funds" to existing users. +Wallet's which currently support the ‎m/48' 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: + +
+m / purpose' / coin_type' / account' / script_type' / change / address_index
+
+ +h or ' 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 0 for mainnet and 1 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 script_type(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: +1': Nested Segwit (p2sh-p2wsh) m/48'/0'/0'/1'
+ +The following path represents Native Segwit (p2wsh) mainnet, account 0: +2': Native Segwit (p2wsh) m/48'/0'/0'/2'
+ +The recommended default for wallets is pay to witness script hash m/48'/0'/0'/2'. + +To add new script types submit a PR to this specification and include it in the list above: +X': Future script type m/48'/0'/0'/X'
+ +===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]]