Managing multiple Bitcoin wallets can be a hassle, especially when it comes to backing up each one separately. BIP-85 (Bitcoin Improvement Proposal 85) offers a solution by letting you create many independent wallets—called child keys—from one single master seed. This greatly simplifies backup and improves overall wallet security.
One master seed, many wallets
BIP-85 introduces a standardized method for generating new mnemonic phrases (the 12, 18, or 24-word backups used in Bitcoin wallets) from a single existing seed. These new phrases act like fully independent wallets, each with its own private keys and addresses.
You only need to securely store the master seed. Any wallet created from it can always be regenerated later using the same parameters, which removes the need for separate backups.
One-way derivation for security
The process of creating child keys from the master seed is one-way. That means:
- You can use the master seed to derive any number of child wallets.
- But you cannot reverse the process to find the master seed from a child wallet.
This ensures that even if one of your child wallets is compromised, your master seed—and any other wallets derived from it—stay safe.
Where is BIP-85 used?
BIP-85 is a standardized protocol and is supported by wallets like the BitBox02 hardware wallet. Thanks to this standard, child keys created on one BIP-85-compatible device can also be used on others.