It runs from there like an app, works offline, and keeps your keys on this phone.
Already added it? Open CipherMath from your Home Screen. Safari and the Home Screen app keep separate data.
Encrypt text here, send it through WhatsApp, SMS or email. Only the person who shares your key can read it.
6 digits. It unlocks your keys on this phone.
Keys live only on this phone, with no backup yet. Deleting CipherMath erases them, and contacts would need to share keys again.
Unlocks your contacts and keys
Add a contact first. You'll agree on a shared key with them, then encrypt messages they can read.
Not saved. Disappears when you leave this screen.
No contacts yet. Add someone you want to message privately. You'll set up a shared key together, by phone or in person.
Each contact has their own key, stored only on this phone and locked with your PIN.
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Showing the key asks for your PIN.If someone gets into your WhatsApp, email or a backup, they only see scrambled text. Only a phone that has your shared key can turn it back into words.
You and each contact agree on a key, ideally 4 random words read aloud by phone or in person. Never send a key through the same app as your messages.
Messages are encrypted with AES-256-GCM, which also detects tampering. Your shared key is stretched with PBKDF2-SHA256 (600,000 rounds), and every message gets its own random salt and key through HKDF. It all runs on your phone using the browser's built-in Web Crypto.
Contacts and keys are stored only on this phone, encrypted with a key made from your PIN. Nothing is sent to any server. CipherMath works with no internet connection.
It can't help if your phone itself is compromised, for example by malware or someone using it while unlocked. Messaging apps can still see who you message and when. There's no backup yet: deleting CipherMath erases your keys.