Private key management
How BSV wallets protect and back up the master key, and which page to read for what you are building.
A BSV wallet holds one master private key and derives every other key from it. Protecting that one secret, without making it so hard to reach that people lose it, is most of what a wallet does.
These pages cover how that works and what each choice costs.
Start here
Read the Overview first. It covers what a BSV wallet actually holds, how key derivation works, where the master key comes from, and the four ways products control who can sign (single key, multi-key, external signer, shared).
The pages
Who can sign:
- Multi-key: several keys, a set number of which must sign. For savings, shared money and inheritance.
- External signers: the key on a device that never goes online.
How the secret is backed up:
- Manual backup: recovery words or backup shares, written down and kept by the user. Every other method falls back to it.
- Automatic cloud backup: an encrypted backup held by a service, so losing a phone does not mean losing the money.
The one thing to take away
The key is only half of a backup. Keys are derived per payment from details that are not on the blockchain, so a restored key may not know which outputs belong to the user. The wallet's own records are the other half, and a product that backs up only the words leaves its users restoring a wallet that looks empty. See Backups.
Related
- Backups: what a complete backup contains
- Wallet setups: which wallet should hold what
- Daily spending wallet: backup and recovery
Written from: BRC-42, BRC-75, BRC-100, BRC-140, BRC-157.