It's live. Quldra is a post-quantum, single-device, no-phone-number, no-email messenger. iOS, Androidm, and a possibility to have web-chats through the app. Took me around 8 months to get to this point.

This post is what it is, how it's uilt, and the trade-offs I made along the way. The three previous posts in this series cover the details of some of the pieces - I've linked them inline.

What it is?

End-to-end encrypted , with ML-KEM-768 (NIST FIPS 203, the post-quantum standard) for key exchange and ChaCha20-Poly1305 for message and media encryption.

Single-device per account , enforced server-side by a fingerprint hash on every request. If you recover onto a new device, the old one hard-resets within 8 seconds.

No phone number, no email . Accounts are usernames with a recovery code. I do not have a way to reach you, and I prefer it that way.

DMs, group chats, and invite-based group joining.…