Home Page
DI Management Services is a computer programming consultancy based in Australia and run by David Ireland. This is our home page. There is a Site Map listing things more concisely and more info on the site here. To contact us follow the contact links below.
What we do
We do three things:
What's new?
- 12 May 2013.
Brand new bdcalc calculator for large natural numbers.
- 27 April 2013. New version 2.4 of our free ANSI C BigDigits library to do arithmetic and number theoretical calculations with large integers.
- 25 April 2013. Statistics: An on-line calculator for the binomial distribution.
- 22 March 2013. Updated the Converting from lex & yacc to flex & bison page and added Using flex and bison in MSVC++ .
- 4 March 2013. Number theory: Updated the Dirichlet character table generator
- 15 February 2013. Cryptography: Encrypting credit card numbers using Feistel Finite Set Encryption Mode (FFSEM)
- 29 January 2013. Updated version 3.9.3 of the CryptoSys PKI Toolkit released.
- 15 January 2013. Statistics: An on-line calculator for the chi-square distribution.
- 6 December 2012. New version 1.5.2 of Wclock released.
- 19 November 2012. Set theory: De Morgan's laws explained in graphical form.
- 7 November 2012. New version 4.6 of CryptoSys API released, with SHA-3.
- 2 November 2012. Cryptography: Test vectors for HMAC-SHA-3.
- 22 October 2012. Cryptography: Test vectors for SHA-1, SHA-2 and SHA-3 including Kaccak the new winner of the SHA-3 competition.
- 25 September 2012. Upgrade 5.1.2a of FirmaSAT released.
- 1 June 2012. Linear algebra: The theory behind Transforming a matrix to reduced row echelon form.
- 15 May 2012. Linear algebra: Added matrix calculator Transform matrix to row canonical form also called reduced row echelon form (RREF).
- 9 May 2012. Cryptography: Signing an XML document using XMLDSIG (Part 2).
- 18 November 2011. Coding Theory: Added matrix calculator Transforming a generator matrix to standard form.
- 17 November 2011. Number theory: Updated the Euclidean Algorithm page with code showing how to use the binary GCD algorithm.
- 11-11-11. New version 2.3 of our BigDigits free source code and a new version of our Modular Arithmetic Freeware to do modular arithmetic calculations with large integers.
- 3 November 2011. Number theory: Complete re-write of RSA Theory page and a new mathematics page on Elementary Number Theory.
- August 2011. We have moved from Sydney to south-west Western Australia.
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 (re-written 2010-08-28), and
Cross-Platform Encryption.
We also publish cryptography-related articles on Mathematics.
...more details →
CryptoSys Products
We sell two commercial cryptographic products under the CryptoSysTM brand name:
CryptoSys API and the
CryptoSys PKI Toolkit.
CryptoSys API is library of symmetrical cryptography tools
and the CryptoSys PKI Toolkit 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
VB6/VBA, VB.NET/VB2005/VB2008, C/C++, C# and (for CryptoSys API) ActiveX/COM/VBScript.
...more details →
Consulting
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.
...more details →
Database design
We have been providing database solutions to small and medium enterprises for many years.
We use our extensive library of Microsoft Access techniques as a base to provide customised solutions that actually work.
We don't sell "off-the-shelf" database solutions. All our projects are customised individually for clients with specific problems.
...more details →
To find out more about recent projects we have carried out see Projects.
There are some how-to pages on Using class modules in Access that we put together a few years ago for Access 97 - it's still valid for all the more recent versions of Access. We also describe our experiences in Upgrading from Access 97 to 2003. Although a bit dated now, we show how to use SQL Server on Win98, and a simple graphical OSQL Interface to MSDE from an Access database.
Our links page has some useful info on Microsoft Access and VB Programming.
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# and Perl. Why use professional programming services?
For more details of our experience see Profile, Projects and Computer Experience.
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.
...more details →
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++.
Examples
- Wclock is a free, customisable, always-on-top world time clock for Win32 computers. The full source code is provided.
- BigDigits is a free library of multiple-precision arithmetic routines written in ANSI C to carry out large natural number calculations.
- DBXanalyzerTM reads, analyses and manages email data files created by Microsoft Outlook Express 5 and 6. It has a simple GUI interface and is used by hundreds of happy users worldwide to recover and manage their old Outlook Express emails. You can download a trial version.
- Our Su Doku Solver was written in Excel VBA back in 2004 when the "fiendish" puzzles were first introduced by the Times. This solver will solve almost all Su Doku problems (and takes away all the fun!).
Contact
Contact: Email Us Client Login Payments
This page last updated 20 May 2013
