Sincerus security and privacy
Sincerus keeps the private parts on your iPhone: chats are end-to-end encrypted and Face ID never leaves the device.
Updated
Are Sincerus chats end-to-end encrypted?
Yes. Sincerus chats use the X3DH key agreement and the Double Ratchet, the published designs Signal introduced, implemented with Apple’s CryptoKit. Messages are encrypted on your iPhone and can only be decrypted on the other person’s. The Sincerus server relays encrypted messages and can’t read them.
What chat protections does Sincerus have?
Safety numbers
Compare one with a friend to make sure no one is in between.
Disappearing messages
Set a timer and messages delete themselves.
Chat Lock
A secret code and Face ID keep chosen chats out of sight.
Confirmed sending
Sending a message needs the same device confirmation as a post, so scripts can’t message you.
Where are my Sincerus messages stored?
On your iPhone. The server holds an encrypted message only until your device collects it, and deletes it then, or after 30 days if it is never collected. A Sincerus account uses one device at a time, so your history lives on that iPhone.
What does the Sincerus server keep?
- Your profile, your published posts and their labels.
- The App Attest key that signs your posts. Never your face or fingerprint.
- Traffic logs (IP address, port and time) for 24 months, as Turkish Law No. 5651 requires.
Everything is listed in the privacy policy, with how long each item is kept.
How do I protect my Sincerus account?
You sign in with your Apple Account, so your Sincerus account has the same protection as your Apple Account, including two-factor authentication. Keep a passcode on your iPhone: it is what confirms your posts and messages.
How do I report a security problem?
Email support@sincerus.app. For child-safety reports, email safety@sincerus.app.
Sincerus is a social network for iPhone where every post is typed by a person and confirmed with Face ID. No bots, no AI-written posts.