Authenticated encryption with Apple CryptoKit. If the encrypted text is altered, decryption fails instead of returning a wrong message.
Hush
Encrypt your message before it leaves your phone.
Hush turns text into encrypted text on your device using a secret you and one other person share. Paste the result into Messages, Mail, or Notes. The other person pastes it back into Hush with the same secret to read it. Encryption and decryption happen entirely on each device.
Your secret is turned into a key with PBKDF2-HMAC-SHA256 at 600,000 iterations, replacing the old fast method so weak secrets are far harder to brute-force.
Generate a passphrase from the EFF diceware wordlist of 7,776 words, with a live strength and crack-time meter so you can see how strong your secret really is.
Name and save secrets like "Family" or "Work" in the iOS Keychain, protected by Face ID, Touch ID, or your passcode. Stored on this device only, never synced.
Show a secret or a short encrypted message as a QR code so the other person can scan it face to face, generated on device and sent nowhere.
Hush can automatically clear the clipboard a short time after you copy, so decrypted text does not linger where other apps can read it.
New messages use the HUSH2 format. Messages created with older versions of Hush still decrypt automatically.
A built-in guide and crypto glossary explain AES-256-GCM, key derivation, what a HUSH2 package contains, and how to choose a strong secret.
No account, no server, no analytics, and no tracking. Hush protects message text and nothing about it leaves your device.
Hush protects the contents of a message, not the fact that you sent one, and it cannot recover a message if the secret is lost — there is no backdoor, by design. It is a focused tool to keep message text private between two people who share a secret.