CIP-0011

Staking key chain for HD wallets

Status
Active
Category
Wallets
Created
License
CC-BY-4.0
Authors
Sebastien GuillemotMatthias Benkort
Implementors
N/A
Discussions
Discussion 1Discussion 2Discussion 3

Abstract

Starting with the Shelley hardfork, Cardano makes use of both the UTXO model and the account model. To support both transaction models from the same master key, we allocate a new chain for CIP-1852.

Motivation: why is this CIP necessary?

Generally it's best to only use a cryptographic key for a single purpose, and so it's best to make the staking key be separate from any key used for UTXO addresses.

Specification

Note The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in RFC 2119.

Recall that CIP-1852 specifies the following derivation path:

m / purpose' / coin_type' / account' / chain / address_index

We set chain=2 to indicate the staking key chain. Keys in this chain MUST follow the accounting model for transactions and SHOULD be used for reward addresses

Test vectors

recovery phrase

prevent company field green slot measure chief hero apple task eagle sunset endorse dress seed

private key (including chaincode) for m / 1852' / 1815' / 0' / 2 / 0

b8ab42f1aacbcdb3ae858e3a3df88142b3ed27a2d3f432024e0d943fc1e597442d57545d84c8db2820b11509d944093bc605350e60c533b8886a405bd59eed6dcf356648fe9e9219d83e989c8ff5b5b337e2897b6554c1ab4e636de791fe5427

reward address (with network_id=1)

stake1uy8ykk8dzmeqxm05znz65nhr80m0k3gxnjvdngf8azh6sjc6hyh36

Rationale: how does this CIP achieve its goals?

Meaning of account

The term "account" is unfortunately an overloaded term so we clarify all its uses here:

1) "Account" as a BIP44 derivation level

BIP44 uses the term "account" as one derivation level to mean the following

This level splits the key space into independent user identities, so the wallet never mixes the coins across different accounts. To differentiate this from other usage, we sometimes refer to it as an account' (the bip32 notation) or a BIP44 Account.

2) "Account" as a transaction model

Blockchains like Ethereum does not use the UTXO model and instead uses the Account model for transactions.

Path to Active

Acceptance Criteria

  • All notable wallet and tooling providers follow this method of key derivation.

Implementation Plan

  • This method of key derivation has been agreed as canonical and has been included in CIP-1852.
  • This method of key derivation has been supported by all wallet and tool providers beginning with the Shelley ledger era.

This CIP is licensed under CC-BY-4.0.