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CryptoSys cryptography software tools for developers

The CryptoSys^TM family of programming interfaces provides cryptography toolkits for developers [NEW WEB SITE]

CryptoSys PQC | CryptoSys PKI | CryptoSys API | SC14N | Xmlsq | diQRcode | FirmaSAT | What's new? | See also | FAQ | llms.txt | Contact us

Post-quantum cryptography

CryptoSys PQC provides the three NIST-approved post quantum cryptography algorithms ML-KEM, for public key encryption, and ML-DSA and SLH-DSA for public key digital signature schemes. This is a free library.
New

New

2025-05-24.

Public key cryptography

CryptoSys PKI Pro is a library to carry out public key cryptography using RSA and ECDSA. You can generate and manage X.509 certificates, PKCS#8/PKCS#12 private keys and CMS/PKCS#7 objects. Includes all required supporting cryptographic utilities.

Symmetric cryptography

CryptoSys API provides "symmetrical" encryption using block ciphers like AES and Triple DES; stream ciphers ArcFour, Salsa and ChaCha20; message authentication algorithms HMAC, CMAC and KMAC; hash functions SHA-1, SHA-2 and SHA-3; and more.

XML canonicalization

SC14N performs the canonicalization (C14N) transformation you need to do when creating signed XML documents using XML-DSIG. It can carry out both "inclusive" and "exclusive" canonicalization. Includes a command-line interface.

XML simple query

xmlsq is a free simple lightweight utility to query XML documents using XPath 1.0. Use from the command line or via its programming interface.

QR code generator

diQRcode enables you to generate QR code images directly from your code or the command line.

Mexico SAT tax receipts

FirmaSAT is a specialist product to sign and analyze digital tax receipts (Comprobantes Fiscal Digital) as specified by the Servicio de Administración Tributaria (SAT) in Mexico. Includes a command-line interface.

Download Trial Versions for all of the above in one convenient spot.

Just Released PQC 2025-05-24: Introducing CryptoSys PQC our new free Post-quantum cryptography library.

What's New?

2025-05-24: Introducing CryptoSys PQC our new free Post-quantum cryptography library, with support for ML-KEM, ML-DSA and SLH-DSA.
2024-12-18: Updated CryptoSys PKI Linux Version and added new Using CryptoSys PKI with .NET Core on Linux.
2024-12-14. Released updated Version 10.70.36 of FirmaSAT.
2024-09-24. Released new Version 23.0 of CryptoSys PKI Pro with support for RSA-KEM. See New in this version.
2024-09-08. Released updated v1.1 of guiDumpASN1 a Windows GUI built around Peter Gutmann's dumpasn1 code to analyze ASN.1 files.
2024-02-25. A simple lattice-based encryption scheme: the foundation of the post-quantum cryptosystem ML-KEM/Kyber, with Python code.
2024-01-07. Released updated version 6.22.1 of CryptoSys API. See Changes in this version.
2023-04-18. Released a new Python interface to FirmaSAT.
2023-04-14. Added a new Delphi interface to SC14N.
2023-03-17. Introducing SPHINCS+ A stateless hash-based signature scheme (now SLH-DSA): working through a real example of a SPHINCS+ signature, with Python code.
2022-11-15: Released Online XML Digital Signature Verifier to verify XML documents signed using XML-DSIG.
2022-04-05. Released version 3.1 of our XML canonicalization utility SC14N. See New in the latest version.
2022-02-24: New page XML-DSIG signing with CryptoSys PKI and SC14N with companion page Signing an XML document using XMLDSIG (Part 3).
2021-09-25. Released "20th Anniversary Issue" of CryptoSys API Library Version 6.20. See Looking back 20 years.
2021-07-18. Released updated version 1.0.0 of xmlsq, our free XML Simple Query utility. xmlsq is a simple lightweight utility to query XML documents using XPath 1.0.
2021-06-16. Released new version 4.0 of diQRcode our QR code generator with support for GIF, SVG and PDF files and base64 output..
2020-12-20. New page Using an RSA private key in a PEM string to sign data.
2020-12-07. New page Using CryptoSys PKI to encrypt and decrypt using XMLENC and its companion explanatory page Encryption in XML documents using XMLENC.
2020-10-17. Released CryptoSys PKI Pro 2.0. See New features introduced CryptoSys PKI Pro 1.0 to Pro 2.0.
2020-01-17. Note that none of our products is affected by the Windows CryptoAPI vulnerability (CVE-2020-0601). We do not use the Windows CryptoAPI in any way!
2019-12-28. Released new Python interfaces to CryptoSys PKI Pro and SC14N, both updated from Python 2 to Python 3.
2019-09-14. Updated website for FirmaSAT and en español
2018-09-16. Released CryptoSys API Library Version 5.3 with support for SHA-3, SHAKE and KMAC.

See also

See bdcalc our free calculator for the large natural numbers used in cryptography computations. More details and free downloads are available on the bdcalc page.

Contact

For more information, please send us a message.

This page last updated 21 October 2025