specs/status-account-spec.md

Status Account Specification

Version: 0.1 (Draft)

Authors: Corey Petty corey@status.im (alphabetical order)

Summary

The core concept of an account in Status is a set of cryptographic keypairs. Namely, the combination of the following:

1. a whisper chat identity keypair
2. a set of cryptocurrency wallet keypairs

Everything else associated with the contact is either verified or derived from the above items, including:

• Ethereum address (future verification, currently the same base keypair)
• 3 word mnemonic name
• identicon
• message signatures

1 Initial Key Generation

1.1 Public/Private Keypairs

• An ECDSA (secp256k1 curve) public/private keypair MUST be generated via a BIP43 derived path from a BIP39 mnemonic seed phrase.
• The default paths are defined as such:
  • Whisper Chat Key (IK): m/43'/60'/1581'/0'/0 (post Multiaccount integration)
    • following EIP1581
  • DB encryption Key (DBK): m/43'/60'/1581'/1'/0 (post Multiaccount integration)
    • following EIP1581
  • Status Wallet paths: m/44'/60'/0'/0'/i starting at i=0
    • following BIP44
    • NOTE: this (i=0) is also the current (and only) path for Whisper key before Multiaccount integration

1.2 X3DH Prekey bundle creation

• Status follows the X3DH prekey bundle scheme that Open Whisper Systems outlines in their documentation with the following exceptions:
  • Because there are no central servers, we do not publish one-time keys OPK or perform DH including them.
• A client MUST create X3DH prekey bundles, each defined by the following items:
  • Identity Key: IK
  • Signed prekey: SPK
  • Prekey signature: Sig(IK, Encode(SPK))
  • Timestamp
• These bundles are made available in a variety of ways, as defined in section 2.1.

1.3 Register at push notification system

• TODO: Add this.

2 Account Broadcasting

• A user is responsible for broadcasting certain information publicly so that others may contact them.

2.1 X3DH Prekey bundles

• A client SHOULD regenerate a new X3DH prekey bundle every 24 hours. This MAY be done in a lazy way, such that a client that does not come online past this time period does not regenerate or broadcast bundles.
• The current bundle MUST be broadcast on a whisper topic specific to his Identity Key, {IK}-contact-code, intermittently. This MAY be done every 6 hours.
• A bundle MUST accompany every message sent.
• TODO: retreival of long-time offline users bundle via {IK}-contact-code

3 Optional Account additions

3.1 ENS Username

• A user MAY register a public username on the Ethereum Name System (ENS). This username is a user-chosen subdomain of the stateofus.eth ENS registration that maps to their whisper identity key (IK).

3.2 User Chosen Name

• An account MAY create a display name to replace the IK generated 3-word pseudonym in chat screens. This chosen display name will become part of the publicly broadcasted profile of the account.

3.3 User Profile Picture

• An account MAY edit the IK generated identicon with a chosen picture. This picture will become part of the publicly broadcasted profile of the account.

3.4 Tribute to Talk

• TODO - Couched until later

3.5 Wallet Accounts

• TODO (based in multiaccount)

Security Implications