Skip to content
Switch branches/tags
This branch is up to date with master.

Latest commit


Git stats


Failed to load latest commit information.
Latest commit message
Commit time

AppVeyor: Build status image, CircleCI: Build status image, Travis CI: Build status image


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


liboqs provides:

  • a collection of open source implementations of quantum-safe key encapsulation mechanism (KEM) 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 led by Douglas Stebila and Michele Mosca, 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 TLS and SSH, through OpenSSL and OpenSSH.

More information on OQS can be found here and in the associated whitepapers.


Supported Algorithms

Key encapsulation mechanisms

  • FrodoKEM: FrodoKEM-640-AES, FrodoKEM-640-SHAKE, FrodoKEM-976-AES, FrodoKEM-976-SHAKE, FrodoKEM-1344-AES, FrodoKEM-1344-SHAKE
  • Kyber: Kyber512, Kyber768, Kyber1024, Kyber512-90s, Kyber768-90s, Kyber1024-90s
  • NewHope: NewHope-512-CCA, NewHope-1024-CCA
  • NTRU: NTRU-HPS-2048-509, NTRU-HPS-2048-677, NTRU-HPS-4096-821, NTRU-HRSS-701
  • SABER: LightSaber-KEM, Saber-KEM, FireSaber-KEM
  • SIKE: SIDH-p434, SIDH-p503, SIDH-p610, SIDH-p751, SIKE-p434, SIKE-p503, SIKE-p610, SIKE-p751, SIDH-p434-compressed, SIDH-p503-compressed, SIDH-p610-compressed, SIDH-p751-compressed, SIKE-p434-compressed, SIKE-p503-compressed, SIKE-p610-compressed, SIKE-p751-compressed

Signature schemes

  • Dilithium: Dilithium2, Dilithium3, Dilithium4
  • MQDSS: MQDSS-31-48, MQDSS-31-64
  • Picnic: Picnic-L1-FS, Picnic-L1-UR, Picnic-L3-FS, Picnic-L3-UR, Picnic-L5-FS, Picnic-L5-UR, Picnic2-L1-FS, Picnic2-L3-FS, Picnic2-L5-FS
  • qTesla: qTesla-p-I, qTesla-p-III
  • SPHINCS+-Haraka: SPHINCS+-Haraka-128f-robust, SPHINCS+-Haraka-128f-simple, SPHINCS+-Haraka-128s-robust, SPHINCS+-Haraka-128s-simple, SPHINCS+-Haraka-192f-robust, SPHINCS+-Haraka-192f-simple, SPHINCS+-Haraka-192s-robust, SPHINCS+-Haraka-192s-simple, SPHINCS+-Haraka-256f-robust, SPHINCS+-Haraka-256f-simple, SPHINCS+-Haraka-256s-robust, SPHINCS+-Haraka-256s-simple
  • SPHINCS+-SHA256: SPHINCS+-SHA256-128f-robust, SPHINCS+-SHA256-128f-simple, SPHINCS+-SHA256-128s-robust, SPHINCS+-SHA256-128s-simple, SPHINCS+-SHA256-192f-robust, SPHINCS+-SHA256-192f-simple, SPHINCS+-SHA256-192s-robust, SPHINCS+-SHA256-192s-simple, SPHINCS+-SHA256-256f-robust, SPHINCS+-SHA256-256f-simple, SPHINCS+-SHA256-256s-robust, SPHINCS+-SHA256-256s-simple
  • SPHINCS+-SHAKE256: SPHINCS+-SHAKE256-128f-robust, SPHINCS+-SHAKE256-128f-simple, SPHINCS+-SHAKE256-128s-robust, SPHINCS+-SHAKE256-128s-simple, SPHINCS+-SHAKE256-192f-robust, SPHINCS+-SHAKE256-192f-simple, SPHINCS+-SHAKE256-192s-robust, SPHINCS+-SHAKE256-192s-simple, SPHINCS+-SHAKE256-256f-robust, SPHINCS+-SHAKE256-256f-simple, SPHINCS+-SHAKE256-256s-robust, SPHINCS+-SHAKE256-256s-simple

Limitations and Security

As research advances, the supported algorithms may see rapid changes in their security, and may even prove insecure against both classical and quantum computers.

liboqs does not intend to "pick winners": algorithm support is informed by the NIST Post-Quantum Cryptography Standardization project. We strongly recommend that applications and protocols rely on the outcomes of ths effort when deploying post-quantum cryptography.

We realize some parties may want to deploy quantum-safe cryptography prior to the conclusion of the NIST standardization project. We strongly recommend such attempts make use of so-called hybrid cryptography, in which quantum-safe public-key algorithms are used alongside traditional public key algorithms (like RSA or elliptic curves) so that the solution is at least no less secure than existing traditional cryptography.



  1. Install dependencies:

    On Ubuntu:

     sudo apt install autoconf automake libtool gcc libssl-dev python3-pytest unzip xsltproc doxygen graphviz

    On macOS, using a package manager of your choice (we've picked Homebrew):

     brew install autoconf automake libtool openssl wget doxygen graphviz
     pip3 install pytest
  2. Get the source:

     git clone -b master
     cd liboqs

    and build:

     autoreconf -i
     make clean
     make -j

    Various options can be passed to configure to disable algorithms, use different implementations, specify which OpenSSL library to use, or cross-compile. See ./configure --help for details.

    (If on macOS you encounter an error like Can't exec "libtoolize": No such file or directory at ..., try running with LIBTOOLIZE=glibtoolize autoreconf -i.)

  3. The main build result is liboqs.a, a static library. (This may be placed in the .libs directory.) There are also a variety of programs built under the tests directory:

    • test_kem: Simple test harness for key encapsulation mechanisms
    • test_sig: Simple test harness for key signature schemes
    • kat_kem: Program that generates known answer test (KAT) values for key encapsulation mechanisms using the same procedure as the NIST submission requirements, for checking against submitted KAT values using tests/
    • kat_sig: Program that generates known answer test (KAT) values for signature schemes using the same procedure as the NIST submission requirements, for checking against submitted KAT values using tests/
    • speed_kem: Benchmarking program for key encapsulation mechanisms; see ./speed_kem --help for usage instructions
    • speed_sig: Benchmarking program for signature mechanisms; see ./speed_sig --help for usage instructions
    • example_kem: Minimal runnable example showing the usage of the KEM API
    • example_sig: Minimal runnable example showing the usage of the signature API
    • test_aes, test_sha3: Simple test harnesses for crypto sub-components

    A range of tests (including all test_* and kat_* programs above) can be run using

     python3 -m pytest
  4. To generate HTML documentation of the API, run:

     make docs

    Then open docs/doxygen/html/index.html in your web browser.


Binaries can be generated using the Visual Studio solution in the VisualStudio folder. The supported schemes are defined in the project's winconfig.h file.


Instructions for building on OpenBSD and ARM can be found in the wiki.


Further information can be found in the wiki.


Contributions that meet the acceptance criteria are gratefully welcomed. See our Contributing Guide for more details.


liboqs is licensed under the MIT License; see LICENSE.txt for details.

liboqs includes some third party libraries or modules that are licensed differently; the corresponding subfolder contains the license that applies in that case. In particular:

  • src/crypto/aes/aes_c.c: public domain
  • src/crypto/sha2/sha2_c.c: public domain
  • src/crypto/sha3/fips202.c: CC0 (public domain)
  • src/crypto/sha3/keccak4x: CC0 (public domain), except brg_endian.h
  • src/kem/bike/x86_64: Apache License v2.0
  • src/kem/kyber/pqclean_*: public domain
  • src/kem/newhope/pqclean_*: public domain
  • src/kem/ntru/pqclean_*: public domain
  • src/kem/saber/pqclean_*: public domain
  • src/sig/dilithium/pqclean_*: public domain
  • src/sig/mqdss/pqclean_*: CC0 (public domain)
  • src/sig/picnic/external/sha3: CC0 (public domain)
  • src/sig/rainbow/pqclean_*: CC0 (public domain)
  • src/sig/sphincs/pqclean_*: CC0 (public domain)


Various companies, including Amazon Web Services, evolutionQ, Microsoft Research, and Cisco Systems, have dedicated programmer time to contribute source code to OQS. Various people have contributed source code to liboqs.

Financial support for the development of Open Quantum Safe has been provided by Amazon Web Services and the Tutte Institute for Mathematics and Computing.

Research projects which developed specific components of OQS have been supported by various research grants, including funding from the Natural Sciences and Engineering Research Council of Canada (NSERC); see the source papers for funding acknowledgments.