When you unlock, your master password goes through a deliberately expensive, memory-hard derivation. That cost is the point: it is what makes guessing impractical for someone who has stolen a copy of our database. The result never leaves your device.
How it works
Follow one password from your keyboard to our database.
No metaphors. This is the actual path a secret takes, and the point at which we stop being able to read it.
- 1
Your password becomes a key, on your device
- 2
That key is split in two
One half unlocks your vault. The other proves who you are when signing in. The split is one-way, so the half our servers can see tells them nothing about the half that decrypts.
This is why authenticating and unlocking are separate events — a server that successfully signs you in still cannot read anything you have stored.
- 3
Each item gets its own key
Your account key opens a vault key; the vault key opens an item key; the item key encrypts that item's fields and opens its file keys. Nothing shares a key with anything else.
That buys three things: rotating a vault rewraps a few small keys instead of re-encrypting gigabytes, sharing one item means handing over exactly one key, and deleting something destroys one key — after which its ciphertext is permanently unreadable.
- 4
Only ciphertext is sent
The request that saves a password contains an opaque blob. So does the item's title, its username, its notes, and the name of every file attached to it. Our servers store what they are given and can enumerate structure, enforce access and count usage — nothing more.
- 5
You can check this yourself
The repository ships a seed script that creates demonstration data through the real encryption path, and a one-line command that searches a complete database dump for those demo secrets. The expected result is zero matches. Verification you can run beats assurance you have to take on faith.
Where this stops
Encryption protects data in our custody. It does not protect a device that is already compromised, and we would rather say so here than let you find out later.
What this covers
A full compromise of our database, object storage, servers and operator accounts yields ciphertext and metadata — not your secrets. That is a specific, testable property, and the tests are in the repository.
What it does not
Malware on your own machine, a hostile browser extension, or a weak master password all sit outside what any password manager can defend. We list every limitation.