Show HN: If you lose your memory, how to regain access to your computer?

This is a tool that encrypts files and splits the decryption key among trusted friends using Shamir's Secret Sharing. For example, you can give pieces to 5 friends and require any 3 of them to cooperate to recover the key. No single friend can access your data alone.

Each friend receives a self-contained bundle with recover.html—a browser-based tool that works offline, with no servers or internet required. If this website disappears, recovery still works.

How it works

Your file is encrypted, the key is split into shares, and friends combine shares to recover it.

Different friend combinations can recover the file (any 3 of 5)

Your File → Encrypt → Split key into 5 shares → Distribute to friends

What this is and isn't

Try it in 2 minutes

1. Download the demo bundles (contains 3 sample bundles)
2. Open bundle-alice/recover.html in your browser
3. Add Bob's and Carol's shares (drag their README.txt files onto the page)
4. Watch the automatic decryption when threshold is met

This is the best way to understand what your friends would experience during a real recovery.

On trust and verification

• The code is open source—you can read it on GitHub
• There's a self-audit document explaining the cryptographic choices
• Everything runs locally in your browser; your files don't leave your device
• Try the demo bundles first to see exactly how it works before using it with real secrets
• Uses age for encryption—a well-regarded modern tool

Why I built this

I wanted a way to ensure trusted friends could access important files if something happened to me—without trusting any single person or service with everything. Shamir's Secret Sharing seemed like the right approach, but I couldn't find a tool that gave friends a simple, self-contained way to recover files together. So I built one. I'm sharing it in case it's useful to others.