How Horcrux works

Horcrux vaults require multiple keys to open — and you decide how many. Horcrux helps you create those keys and give one to each person you trust (your stewards).

Under the hood, Horcrux uses an algorithm named Shamir's Secret Sharing to split your vault data into encrypted "shares." A share is a random-looking chunk of your data that's useless by itself, but can be combined with other shares to decrypt the entire vault. You decide how many shares to generate and how many are needed to decrypt the vault — building in redundancy in case a share is lost or destroyed.

For example, you could invite 5 friends as stewards of your vault but only require 3 of them to agree to open it. If one of them initiates a recovery session, the other 4 stewards are notified and can approve or reject the request. If any 3 approve, the vault unlocks for the initiating steward.

Try it

Stewards 5

Threshold 3

Simulate recovery

Horcrux uses the Nostr protocol to securely transfer shares and metadata between you and your stewards. Instead of a traditional account with an email and password, Nostr gives you an account key that only you know and is never shared with the developers of Horcrux or anyone else. This key encrypts all communication between you and your stewards, so the servers that transfer your share data cannot read your messages at all.

To communicate with your stewards, Horcrux uses Nostr relay servers. By default your vaults use the official Horcrux relay, but you can configure them to use any relay you wish, including one you run yourself.

Horcrux is motivated by the principle that our data doesn't need to be owned and controlled by corporations whose highest value is profit and who we cannot hold accountable. Horcrux is fully open source and free to use and modify as you wish.