Core Cryptographic Library: QSC

Repository: QSC (The Quantum Safe Cryptographic library). QSC is a compact, self-contained C library that supplies the post-quantum primitives used by higher-level protocols, with MISRA-aligned structure, extensive inline documentation, and a comprehensive testing platform.

Typical structure includes Source/, Documentation/, docs/, CMake build files, and Visual Studio project files. The README describes supported primitives such as NIST-standardized KEMs and signatures (ML-KEM, ML-DSA, SLH-DSA), symmetric ciphers (RCS, CSX, AES), XOF/KDFs (SHAKE, cSHAKE), MACs (KMAC, QMAC, HMAC), DRBGs, and test tooling (including deterministic vectors and conformance suites).

Messaging and Tunneling Protocols

QSMP (Quantum Secure Messaging Protocol): QSMP provides authenticated messaging in SIMPLEX and DUPLEX operational modes, integrating post-quantum KEM, signatures, and AEAD within a unified design. Repositories typically expose Source/, docs/, build metadata, and links to formal specifications and help documentation.

QSTP and DKTP (Service Tunneling): DKTP focuses on high-assurance tunneling, combining post-quantum asymmetric exchange with directional pre-shared secrets and separate TX/RX channel keys. The repository generally includes documents, source, docs/, and tagged releases intended to support reproducible audits.

Key Distribution and Federation

SKDP (Symmetric Key Distribution Protocol): SKDP supplies a lightweight symmetric handshake with a hierarchical derivation model. Documentation typically covers authentication and token exchange, ephemeral session keys, forward secrecy, and platform build notes (CMake, MSVC, Clang, GCC, plus SIMD guidance where applicable).

MPDC (Multi Party Domain Cryptosystem): MPDC implements multi-party key exchange and policy-anchored federation for distributed systems, with references to specifications, hosted docs, and releases.

HKDS (Hierarchical Key Distribution System): HKDS focuses on deterministic key hierarchies and offline provisioning, usually exposing Source/, Documents/, and docs/.

PQS (Post Quantum Shell): PQS implements a post-quantum secure shell protocol for authenticated command, control, and automation, combining post-quantum primitives with RCS-based authenticated encryption for end-to-end confidentiality and integrity.

SATP (Symmetric Authenticated Tunneling Protocol): SATP provides a symmetric tunneling framework that emphasizes deterministic, low-latency security with authenticated encryption and SHAKE-based derivation.

Common Repository Traits

• Language and build: C implementations with CMake build systems, often supplemented with IDE projects and platform guidance for SIMD.
• Documentation: hosted help docs, technical specifications, and summaries that are kept aligned with the code.
• Testing and vectors: deterministic tests, KATs, fuzz and conformance scaffolding, plus reproducible transcripts where appropriate.
• Licensing and security policy: license files and security policy entries, plus standard repository hygiene for audits.
• Releases: tagged releases to anchor due diligence, binary reproduction, and long-term regression testing.

Repository Navigation Guide

For cryptographic review, begin with QSC to corroborate primitive behavior, vector packs, and platform notes. Next, move to protocol repositories aligned to your domain, for example QSMP for messaging channels, QSTP and DKTP for tunnels, SKDP and HKDS for symmetric keying and provisioning, MPDC for federation. Compare docs/ against the implementation paths in Source/, and confirm that configuration strings, constants, endianness, counter behavior, and build flags are consistent across dependencies.

Integration and CI Hints

• Dependency alignment: build QSC and the consuming protocol under the same compiler and SIMD family settings to prevent ABI and performance mismatches.
• Deterministic configurations: prefer configuration-bound suites that remove runtime negotiation and reduce downgrade exposure.
• Audit artifacts: capture build hashes and vector outputs per release to form a minimal evidence chain from source to binaries.

Conclusion

The QRCS GitHub portfolio provides a structured route from primitives to protocols: QSC defines the building blocks, SKDP and HKDS manage symmetric provisioning, QSMP and tunneling protocols secure message and transport paths, and MPDC provides federation and policy anchoring. With tagged releases, hosted documentation, deterministic tests, and portable CMake builds, the repositories are engineered for independent verification and operational adoption.