How it works
Locks inside locks, so no single key opens everything.
Calyx uses envelope encryption: your passphrase unlocks a key, that key unlocks another, and only the last one ever touches your data. It's why forgetting your passphrase can't lose your history - and why Calyx can never read a thing.
It starts with your passphrase - and it stays on your device.
Never transmitted, never stored. The one secret Calyx is built never to receive.
It gets turned into a key.
Argon2id - slow and memory-hard - derives a key-encryption key (KEK) from your passphrase.
That key unlocks your private key.
The KEK unwraps your X25519 private key. It only ever touches keys, never your data.
Which unlocks each env's own key.
Your private key unwraps a random per-env data key (DEK), sealed to you with a libsodium sealed box.
Which finally encrypts your secrets.
AES-GCM-256. The ciphertext is the only thing that ever reaches the server.
What this design gets you.
The layered keys aren't just for show - they're what make these everyday things simple, and the impossible ones honest.
Changing your passphrase is instant
Your passphrase only locks your private key, not your data. Change it and Calyx just re-wraps that one key - your secrets and full history don't move.
Sharing is the same as reading
“You can read this env” means the key is sealed to your device. “You shared it” means it's sealed to theirs too. Same operation - no plaintext in between.
Recovery is a spare key, not a backdoor
At setup you get a one-time recovery key - a second copy of your private key. It's your only way back in if you forget your passphrase, and it lives with you, not Calyx.
The honest part
What zero-knowledge costs you.
Forget your passphrase and lose your recovery key, and your data's gone. Not gone-till-you-contact-support - gone. Calyx can't reset what it never had.
That's the trade, on purpose. Anything that can recover your secrets for you can be forced to hand them over. Calyx is built so it can't.
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Free for one developer, forever. First encrypted env in under a minute.