Is chat really end-to-end encrypted?
Yes — every message is end-to-end encrypted
We — and nobody else — can never read your conversations. This is built in technically; it's not just a promise.
What does end-to-end encryption mean?
- Messages are encrypted on your phone before they leave the app
- They can only be decrypted on the recipient's phone
- Our servers only see encrypted ciphertext — completely unreadable to us
- Even if a court ordered us to hand over content, we technically can't
Which technology do we use?
- NaCl Box (libsodium) — a well-vetted cryptographic standard
- Curve25519 key pairs for key exchange
- XSalsa20-Poly1305 for the encryption itself (the same approach used by e.g. Signal and WhatsApp for sharing)
- Argon2id to protect your key backup with your password
What we do see:
- That a conversation exists between you and another user (so we can show a chat list)
- Message timestamps
- Whether a message is delivered/read
What we do NOT see:
- Message content — ever, at any moment
- Attachments or photos you might send in the future
- Who wrote what
Also see "What is a private key?" and "Why do I have to enter my password?" for more technical details.
