liboqs

liboqs

liboqs is an open source C library for quantum-safe cryptographic algorithms.

• liboqs
  • Overview
  • Status
    • Supported Algorithms
      • Key encapsulation mechanisms
      • Signature schemes
      • Stateful signature schemes
    • Limitations and Security
      • Platform limitations
      • Support limitations
  • Quickstart
    • Linux and Mac
    • Windows
    • Cross compilation
  • Documentation
  • Contributing
  • License
  • Acknowledgements

Overview

liboqs provides:

• a collection of open source implementations of quantum-safe key encapsulation mechanisms (KEMs) and digital signature algorithms; the full list can be found below
• a common API for these algorithms
• a test harness and benchmarking routines

liboqs is part of the Open Quantum Safe (OQS) project, which aims to develop and integrate into applications quantum-safe cryptography to facilitate deployment and testing in real world contexts. In particular, OQS provides prototype integrations of liboqs into protocols like TLS, X.509, and S/MIME, through our OpenSSL 3 Provider and we provide a variety of other post-quantum-enabled demos.

The OQS project is supported by the Post-Quantum Cryptography Alliance as part of the Linux Foundation. More information about the Open Quantum Safe project can be found at openquantumsafe.org.

OQS is running a survey to better understand our community. We would like to hear from organizations and individuals about their interest in and use of the Open Quantum Safe project. Please take a few minutes to fill out the survey: https://linuxfoundation.surveymonkey.com/r/oqssurvey

Status

Supported Algorithms

The table below summarizes every algorithm family currently integrated into liboqs. For per-variant detail (including NIST level, constant-time status, formal verification, and available optimizations), see ALGORITHMS.md; for upstream sources and advisories, see the per-algorithm pages under docs/algorithms.

Names of algorithms standardized by NIST — ML-KEM, ML-DSA, and SLH-DSA — are stable; if NIST changes the implementation details, liboqs will adjust so that users are protected from such changes. All other names are subject to change. Which algorithms are built can be controlled via OQS_ALGS_ENABLED; by default, liboqs is built supporting every algorithm in the table, including experimental ones.

Key encapsulation mechanisms

Algorithm family Standardization status Primary implementation Upstream maintenance OQS tier BIKE Not selected by NIST awslabs/bike-kem TBD Tier 3 (Community) Classic McEliece Under ISO consideration PQClean/PQClean@1eacfda No active maintenance Tier 3 (Community) FrodoKEM Under ISO consideration microsoft/PQCrypto-LWEKE@a2f9dec Best effort Tier 2 (Supported) HQC Selected by NIST for upcoming standardization pqc-hqc/hqc@161cd4f TBD Tier 2 (Supported) Kyber Selected by NIST as basis for ML-KEM (FIPS 203) pq-crystals/kyber@441c051 Actively maintained Tier 3 (Community) ML-KEM Standardized by NIST pq-code-package/mlkem-native@d1b2fe7 Actively maintained Tier 1 (Core) NTRU Not selected by NIST, under standardization consideration by NTT PQClean/PQClean@4c9e5a3 Actively maintained Tier 3 (Community) NTRU-Prime Not selected by NIST openssh/openssh-portable Actively maintained Tier 3 (Community)

Signature schemes

Algorithm family Standardization status Primary implementation Upstream maintenance OQS tier CROSS Under NIST consideration CROSS-signature/CROSS-lib-oqs@ce9933c Actively maintained Tier 3 (Community) Falcon Selected by NIST for upcoming standardization PQClean/PQClean@1eacfda TBD Tier 3 (Community) MAYO Under NIST consideration [PQCMayo/MAYO-C@74de637](https://github.com/PQCMayo/MAYO-C/commit/74de637a7c4a7f9fafa888183bc05f5cf920cd