[bitcoin-dev] BIP proposal draft: BIP43 "purpose" allocation for Ethereum

[Nick Johnson via bitcoin-dev]

<pre>
BIP: bip-nickjohnson-ethereum-purpose
Layer: Applications
Title: Ethereum purpose allocation for Deterministic Wallets
Author: Nick Johnson <***@ethereum.org>
Status: Proposed
Type: Standards Track
Created: 2017-04-12
</pre>

==Abstract==

This BIP defines a logical hierarchy for deterministic wallets on the Ethereum
blockchain based on an algorithm described in BIP-0032 (BIP32 from now on) and
purpose scheme described in BIP-0043 (BIP43 from now on).

This BIP is a particular application of BIP43.

==Motivation==

Because Ethereum is based on account balances rather than UTXO, the hierarchy
defined by BIP44 is poorly suited. As a result, several competing
derivation path strategies have sprung up for deterministic wallets, resulting
in inter-client incompatibility. This BIP seeks to provide a path to standardise
this in a fashion better suited to Ethereum's unique requirements.

==Path levels==

We define the following 2 levels in BIP32 path:

<pre>
m / purpose' / subpurpose' / *
</pre>

Apostrophe 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 the hardened value of the BIP number assigned to
this BIP (equivalently, the BIP number, bitwise ORed with 0x80000000) 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.

===Subpurpose===
Subpurpose is set to the EIP number specifying the remainder of the BIP32
derivation path. This permits new Ethereum-focused applications of
deterministic wallets without needing to interface with the BIP process.

Hardened derivation is used at this level.

==Reference== * [[bip-0032.mediawiki|BIP32 - Hierarchical Deterministic
Wallets]] * [[bip-0043.mediawiki|BIP43 - Purpose Field for Deterministic
Wallets]]

[Tom Zander via bitcoin-dev]

Thinking about this a bit, I support this proposal for a BIP.
This is not Bitcoin, but address types are bound to meet in meat-space and
it would be good to have a central place where this is defined.

I would very much appreciate someone that worked on BIP32/BIP43 itself to
comment on the details.

Quoting bip 43;


"We encourage different schemes to apply for assigning a separate BIP
number and use the same number for purpose field, so addresses won't be
generated from overlapping BIP32 spaces."



On Wednesday, 12 April 2017 12:02:37 CEST Nick Johnson via bitcoin-dev

Post by Nick Johnson via bitcoin-dev
<pre>
BIP: bip-nickjohnson-ethereum-purpose
Layer: Applications
Title: Ethereum purpose allocation for Deterministic Wallets
Status: Proposed
Type: Standards Track
Created: 2017-04-12
</pre>
==Abstract==
This BIP defines a logical hierarchy for deterministic wallets on the
Ethereum blockchain based on an algorithm described in BIP-0032 (BIP32
from now on) and purpose scheme described in BIP-0043 (BIP43 from now
on).
This BIP is a particular application of BIP43.
==Motivation==
Because Ethereum is based on account balances rather than UTXO, the
hierarchy defined by BIP44 is poorly suited. As a result, several
competing derivation path strategies have sprung up for deterministic
wallets, resulting in inter-client incompatibility. This BIP seeks to
provide a path to standardise this in a fashion better suited to
Ethereum's unique requirements.
==Path levels==
<pre>
m / purpose' / subpurpose' / *
</pre>
Apostrophe 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 the hardened value of the BIP number assigned
to this BIP (equivalently, the BIP number, bitwise ORed with 0x80000000)
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.
===Subpurpose===
Subpurpose is set to the EIP number specifying the remainder of the BIP32
derivation path. This permits new Ethereum-focused applications of
deterministic wallets without needing to interface with the BIP process.
Hardened derivation is used at this level.
==Reference== * [[bip-0032.mediawiki|BIP32 - Hierarchical Deterministic
Wallets]] * [[bip-0043.mediawiki|BIP43 - Purpose Field for Deterministic
Wallets]]