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DI Management Services is a computer programming consultancy based in Australia and run by David Ireland. This is our home page. The Site Map lists things more concisely, and more info on the site is here. To contact us, please send us a message.

What we do


We do three things:

  1. Cryptography programming
  2. General computer programming
  3. Publish various articles on interesting topics in cryptography and mathematics.

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Cryptography programming

We maintain a detailed cryptography software page with useful free cryptographic software code and various articles on cryptography. The free code includes the Blowfish algorithm in VB6 and the MySecret command-line freeware encryption utility. The articles include our page on the RSA Algorithm including the Theory and proof of the RSA algorithm, and various how-to pages such as Using Keys in Cryptography, Using Padding in Encryption, Encryption with International Character Sets, and Cross-Platform Encryption. We also publish cryptography-related articles on Mathematics.
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CryptoSys Products

We sell two commercial cryptographic products under the CryptoSysTM brand name: CryptoSys API and CryptoSys PKI Pro. CryptoSys API is a library of symmetrical cryptography tools and CryptoSys PKI Pro provides public key encryption and digital signatures. FirmaSAT is a separate product to create and read digital receipts specifically for the Tax Administration Service in Mexico (SAT). There are interfaces for programmers in VBA/VB6, VB.NET/VB2005/VB20xx, C/C++, C#, Java and Python.
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We can provide consulting services on implementing cryptography in your programs. In particular, we are happy to provide detailed programming help with implementing CryptoSys API and the CryptoSys PKI Toolkit.
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General computer programming

Just need someone to cut some code? Our founder David Ireland, GSSP-C, has many years experience in programming in a variety of languages, including C, Visual Basic, Microsoft Access, C#, Perl and Python..

For more details of our experience, see Profile and Projects.

We enjoy doing complex algorithms and arcane problems. If we can't do it, we'll tell you up-front, so as not to waste your time. We only start jobs we know we can finish.
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See our page on the C Programming Language where we've assembled links and copies of interesting or educational articles on C programming, look at Windows Win32 programming, and consider why we still prefer ANSI C to C++.


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To contact us, please send us a message.

This page last updated 11 December 2017