Fastcomcorp ZINA is a modern, post-quantum secure messaging protocol suite for mobile devices, representing a second-generation evolution of the original ZINA project.
This software (v1.1.x) supports three generations of protocol logic:
- ZINA PQ-Hybrid (Protocol v3): High-bit classical (X448) + Post-Quantum (ML-KEM/Falcon) hybrid protocol
- Double Ratchet for strong post-compromise security (PCS)
- Sparse ML-KEM (Kyber-based) post-quantum- Metadata Privacy: Encrypted group updates and transport-layer header obfuscation.
- Secure File Transfer: Out-of-band file encapsulation with ratcheted key handover.
- Zeroized Memory: Automatic sanitization of sensitive key material.
- Ed448 EdDSA signatures for cryptographically strong ratchet authentication
- Mandatory ephemerality with burn timers and remote deletion
- Rust-native ports for memory safety (with mandatory Zeroize hardening)
- Compatibility layers with ZRTP for voice/video calls
Originally developed by Silent Circle for their suite of secure applications, the core ZINA protocol (SCimp-inspired) was open-sourced under Apache License 2.0 to foster community review and secure mobile messaging innovation.
Fastcomcorp has revived and significantly upgraded the protocol and library to meet contemporary threats. The latest release incorporates mandatory memory hardening, transport-layer privacy, and post-quantum hybrid key exchange.
Original design and implementation credits:
- The ZINA protocol was a collaboration between Werner Dittmann, Phil Zimmermann, and Travis Cross.
- Initial libzina implementation by Werner Dittmann (Silent Circle era, ~2014–2016).
- How ZINA Works: High-level overview of the protocol fundamentals and its evolution to v2.
- Architecture Guide: Technical deep dive into the cryptographic design and internal components.
- Threat Model: Formal security model and risk assessment for reviewers.
- Technical Specification: Formal definition of wire formats and cryptographic primitives.
To begin integrating Fastcomcorp ZINA into your application, review the ZINA Protocol Guide for a conceptual overview and then examine the C/C++ FFI header at rust/zina-api/include/zina_api.h.
Copyright 2016-2026 Silent Circle, LLC & Fastcomcorp, LLC
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
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