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CryptoSys PQC for Windows

CryptoSys PQC is a programmers library that provides support for all three NIST-approved Post Quantum Cryptography (PQC) algorithms: ML-KEM, ML-DSA and SLH-DSA. It is free to use in your applications (commercial or otherwise) for registered users. For more background information about PQC, see Background on Post-Quantum Cryptography (PQC)

Features

Interfaces for C#, VB.NET, C++ (STL), Python, golang and ANSI C
Support for all parameter sets of ML-KEM, ML-DSA and SLH-DSA algorithms
Support for .KeyGen, .Encaps, .Decaps, .Sign and .Verify functions
Support for "pure" and "pre-hash" signature variants
Support for "hedged" and deterministic signatures
Support for "ExternalMu" variant for ML-DSA
Support for both expanded and "seed" keys for ML-DSA and ML-KEM
Full checking of expanded ML-KEM keys before use
Built-in random number generator (RBG) designed to conform to NIST Special Publication 800-90.
Ability to pass known random test values to compare with known test vectors
Passes all test vectors provided by NIST at NIST Test Vectors

Download the Trial Edition

Version 1.0.0 compiled 24 May 2025. Use either

pqc-trial.exe (600 kB) or
pqc-trial.zip (620 kB) .

Unzip the zip file and run the install.exe program inside it, or download the exe program directly and run it.

Please note it is a breach of copyright to put a copy of these installation files on another server or to distribute them in any manner except by providing a link to this page.

The Trial Edition is fully-functional and the download includes test functions in C#, VB.NET, C++ (STL) and ANSI C. The documentation is available online. Please read the licence conditions for the Trial Edition. The trial period is 60 days from the date first installed on your system. Minimum required operating system is Windows XP-SP2 and above (that is, XP/Vista/W7/W8/W10/W11) or Windows Server 2003 and above.

If you register and get a Licence Code, you can download the full Licensed Edition for free.

Trouble installing: If Microsoft Defender Smartscreen gives you a warning, see Unrecognized app error. (TL;DR Click "More info" then "Run anyway"). Check that you see "Publisher: D.I. MANAGEMENT SERVICES PTY LIMITED".

Register for a free Developer's Edition

Go to the CryptoSys PQC Register Page to register for a free Licensed Edition. Registering is free and the developer's licence permits commercial use and royalty-free permission to distribute with your own applications.

Once you have registered and received your unique Licence Code via email, go to the Licensed Download Page to download a full Licensed Edition of CryptoSys PQC.

Documentation

See the Documentation Page.

Examples

For examples of use in various supported programming languages, see the Examples page. This example code is included with the distribution.

Python Interface

The Python interface crsyspqc is distributed separately via the PyPi site. Go to https://pypi.org/project/crsyspqc/

Interface for go programmers

For a go interface to CryptoSys PQC, see our GitHub https://github.com/davidi67/crsyspqc. It includes examples of use and a full set of programs that validate against all the NIST-ACVP test vectors.

References

[FIPS203] National Institute of Standards and Technology, Module-Lattice-based Key-Encapsulation Mechanism Standard. Federal Information Processing Standards Publication (FIPS) NIST FIPS 203, 13 August 2024. (https://doi.org/10.6028/NIST.FIPS.203).
[FIPS204] National Institute of Standards and Technology, Module-Lattice-Based Digital Signature Standard. Federal Information Processing Standards Publication (FIPS) NIST FIPS 204, 13 August 2024. (https://doi.org/10.6028/NIST.FIPS.204).
[FIPS205] National Institute of Standards and Technology, Stateless Hash-Based Digital Signature Standard. Federal Information Processing Standards Publication (FIPS) NIST FIPS 205, 13 August 2024. (https://doi.org/10.6028/NIST.FIPS.205).

Future plans

Will you be adding support for X.509 certificates and CMS objects?: Probably not in this package, but if there is interest we will add those features to our CryptoSys PKI library, when the specifications are finalized. If there is demand. Let us know.
What about support for reading keys from PKCS8 private key files??: Maybe, once the specifications are finalized. But only if there is demand.
What about an interface for VBA?: It is possible to do, but may be messy with all the long strings required for tests and the limitations on long strings in VBA. If you want one, please ask.
We note you don't provide hash functions to compute the hash values for the pre-hash signature variants. Will you add this?: No. It's up to the user to compute the pre-hash values using any of the many hash packages available. Then pass the short hash value and its algorithm identifier.
Our view is that the whole point of a pre-hash signature variant is that the user just passes a short hash digest to the Sign function along with the hash algorithm identifier. If you need to pass the whole 10 TB message then you may as well use the pure signing variant.

Contact us

To contact us, please send us a message. To make a comment on this page, see comments below.