The application CrypTool is a free e-learning application for Windows. You can use it to apply and analyze cryptographic algorithms. The current version of CrypTool (Download) is used all over the world. It supports both contemporary teaching methods at schools and universities as well as awareness training for employees and civil servants.

The current version offers beside others the following highlights:

• Numerous classic and modern cryptographic algorithms (encryption and decryption, key generation, secure passwords, authentication, secure protocols, ...)
• Visualisation of several methods (e.g. Caesar, Enigma, RSA, Diffie-Hellman, digital signatures, AES)
• Cryptanalysis of certain algorithms (e.g. Vigenère, RSA, AES)
• Crypt-analytical measuring methods (e.g. entropy, n-grams, autocorrelation)
• Auxiliary methods (e.g. primality tests, factorisation, base64 coding)
• Tutorial about number theory
• Comprehensive online help
• Supportive script with further information about cryptology

From its original use of information security training for a company, CrypTool has developed into an outstanding open source project for cryptology related topics.

Since spring 2008, the CrypTool project has been operating the Crypto Portal for Teachers. Thus far, the portal is only available in German and is intended to act as a platform for teachers to share teaching materials about cryptology and related links.

Since spring 2009, the CrypTool project has also been operating the webseite CrypTool-Online. This portal gives people interested in cryptology the possiblity to try out a variety of ciphers and encryption methods in their own browser without downloading and installing any kind of software. On this website for first-time users and young people we provide cryptology in an appealing and easy way. For advanced tasks and problems there is still the offline version of CrypTool which can be downloaded and installed.

Currently the CrypTool team is working on two projects intended to become the successors of the current release version CrypTool 1.4.x which has been written in C++. Both follow-up projects use state-of-the-art standards of software development, but are still in beta status:

• CrypTool 2.0 is developed in C# with Visual Studio 2008 (Express Edition) and WPF. In July 2008 the first beta version (for developers and end users) has been released. It is continuously updated. CrypTool 2.0 provides a fully developed architecture and usable cryptographic functionality combined with a pathbreaking drag-and-drop GUI.
• JCrypTool is developed in Java and based on Eclipse RCP. The current beta version (called release candidate RC1a, intended for developers and users) has been released in January 2010. JCrypTool is platform independent (Windows, Linux, Mac) and makes use of the FlexiProvider (a powerful toolkit developed by the TU Darmstadt) and BouncyCastle for the Java Cryptography Architecture JCA.

Volunteers, especially programmers and students planning to write their theses, are always welcome to join in the further development of this world-wide project.