liboqs
A C library of quantum-safe algorithms from the Open Quantum Safe project, released under the MIT licence.
Why this is listed
The library of quantum-safe algorithms is the whole deliverable rather than a component of a product, published under MIT with its C source readable in the open repository.
liboqs is the Open Quantum Safe project's C library for quantum-safe cryptography. The project states that its algorithm implementations are derived from the reference and optimised code submitted to the NIST Post-Quantum Cryptography Standardization Project, some taken directly from the submitting teams and some by way of PQClean.
The project states that it builds on Linux, macOS and Windows, targets x86_64 and ARM (except Windows on ARM64), and works with clang, gcc and the Microsoft compilers. Open Quantum Safe also publishes prototype integrations of liboqs into TLS, X.509 and S/MIME through an OpenSSL 3 provider.
Prototyping, in the project's own words
The repository describes liboqs as a library for prototyping and experimenting with quantum-resistant cryptography. That framing is the project's, not ours, and it is worth carrying into any decision to depend on it.
Sources
Checked against these sources on Sep 3, 2026. Listing is not endorsement, and nothing here is ranked or scored.