Double Ratchet

Hybrid Post-Quantum Message Sealing: X25519 + ML-KEM-1024 in Umbera Messenger with Public Rust Tests

Umbera messenger has open-sourced its cryptographic core and published seven Rust tests that anyone can run to verify its hybrid post-quantum message sealing scheme. The design combines X25519 with ML-KEM-1024 so that an attacker must break both algorithms to decrypt a message. Messages are protected by Double Ratchet for forward secrecy, sealed sender packaging, and per-message ephemeral keys derived via HKDF-SHA256 into AES-256-GCM. The relay server stores only an opaque box identifier and encrypted blob with no sender or recipient fields visible. Media calls use DTLS-SRTP end-to-end while TURN servers see only encrypted datagrams. Addresses for message boxes rotate weekly and are derived solely from the shared secret between the two parties.

Building Prizrak: How a Developer Created a Federated Messenger That Masks All Traffic as Legitimate HTTPS

A developer created Prizrak, a federated messenger with end-to-end encryption where all traffic, including calls, is indistinguishable from ordinary HTTPS connections. The project addresses three common limitations of existing messengers: centralized control points, mandatory phone numbers, and detectable encrypted traffic. It uses real TLS 1.3 handshakes to actual domains, multi-port listening, and a hidden token mechanism inside the encrypted channel. When servers cannot reach each other directly, messages are delivered through a network of storage nodes modeled after Ceph's RADOS system. Voice and video calls run on a native media stack with custom STUN-like functionality and careful UDP buffer sizing to avoid packet truncation. An integrated two-hop VPN reuses the same stealth transport while keeping messenger traffic outside the tunnel.