crsyspqc 1.0.0

Python interface to CryptoSys PQC

This is a Python interface to the CryptoSys PQC library <https://www.cryptosys.net/pqc>.

CryptoSys PQC provides the three Post-Quantum Cryptography (PQC) algorithms specified by NIST in August 2024 considered to be secure against an attack by a large-scale quantum computer. These are

• Module-Lattice-Based Key-Encapsulation Mechanism (ML-KEM) specified in FIPS.203,

• Module-Lattice-Based Digital Signature Algorithm (ML-DSA) specified in FIPS.204, and

• Stateless Hash-based Digital Signature Algorithm (SLH-DSA) specified in FIPS.205.

All keys, signatures and ciphertext values in this library are input and output as byte arrays.

Known random values can be input to validate against test vectors.

For the DSA algorithms, options are provided to use the deterministic or hedged modes, to add a context string, and to use the pre-hash modes HashML-DSA and HashSLH-DSA. For ML-DSA, there is the option to use the ExternalMu-ML-DSA algorithm, passing mu as the message.

For ML-DSA and ML-KEM, the private key can be passed in expanded or “seed” form (the form is automatically detected by the length).

Requires: Python 3. CryptoSys PQC v1.0 or above must be installed on your system. This is available from

https://www.cryptosys.net/pqc

To use in Python’s REPL

Using wild import for simplicity.

>>> from crsyspqc import *  # @UnusedWildImport
>>> General.version() # "hello world!" for CryptoSys PQC
10000
>>> Dsa.privatekey_size(Dsa.Alg.ML_DSA_65)
4032

The stricter way using the crsyspqc prefix.

>>> import crsyspqc
>>> crsyspqc.General.version() # Underlying core CryptoSys PQC dll
10000
>>> crsyspqc.__version__  # crsyspqc.py module version
'1.0.0.0000'
>>> crsyspqc.Dsa.signature_size(crsyspqc.Dsa.Alg.SLH_DSA_SHAKE_256F)
49856

Note that crsyspqc.General.version() gives the version number of the underlying core (native) CryptoSys PQC DLL, and crsyspqc.__version__ gives the version of the Python crsyspqc module.

Examples

There is a series of tests in test_crsyspqc.py (source). You should find an example there of what you want to do.

Contact

For more information or to make suggestions, please contact us at https://www.cryptosys.net/contact/

David Ireland

DI Management Services Pty Ltd t/a CryptoSys

Australia

<https://www.di-mgt.com.au> <https://www.cryptosys.net>

21 May 2025