PrivChat

PrivChat is an encrypted messenger that works without servers.

There is no account to create. No phone number, no email, no name. And there
is no server your conversations pass through: messages travel straight from
your computer to the other person's device over the Tor network.

To talk to someone you need their invitation, and they need yours. You
exchange them by scanning a QR code or passing along a piece of text. There
is no user directory: nobody can find you unless you have given them your
invitation.

What is inside:

• End-to-end encryption with a Double Ratchet, and post-quantum cryptography

(ML-KEM-768 key agreement, ML-DSA-65 signatures).

• Sealed sender: not even who is writing to you travels in the clear.
• Fingerprint verification, in person or over another channel.
• Photos, videos and voice notes, decrypted in memory and never written to

disk in the clear.

• Small serverless groups and broadcast channels.
• Disappearing messages, blocked contacts, pinned messages and polls.
• Local database encrypted with SQLCipher, opened with your passphrase.
• Tor bridges included, with obfs4 for where Tor is blocked.

No ads, no analytics, no trackers and no server of ours. PrivChat also exists
for Android, Windows, macOS and iPhone, and they all speak the same protocol.

More at https://privchat.wiki