What is CrypTool 1

CrypTool 1 (CT1) is an open-source Windows program for cryptography and cryptanalysis. It’s the most wide-spreaded e-learning software of its kind.

What is CrypTool 2?

CrypTool 2 (CT2) is an open-source program offering an innovative visual programming GUI to experiment with cryptographic procedures and to animate their cascades.

What is JCrypTool?

JCrypTool (JCT) is an open-source e-learning platform, allowing to experiment comprehensively with cryptography on Linux, MAC OS X, and Windows.

What is CrypTool-Online?

CrypTool-Online (CTO) runs in a browser and provides a huge variety of encryption methods and analysis tools including many illustrated examples.

What is MysteryTwister C3?

MysteryTwister C3 (MTC3) is an international Crypto Cipher Contest offering a broad variety of challenges, a moderated forum and an ongoing hall-of-fame.

The JCrypTool installation is very simple: download and extract the zip-archive, launch the main program and get started. No administration rights are needed for the installation. Only an installed Java Runtime Environment (JRE) is required.


JCrypTool installation is kept simple: Download the zip (Windows) or tar.gz archive (Linux and macOS) for your platform and your architecture (x86 or x64) and extract it into a folder (e.g. C:\Program Files on Windows, /Applications on macOS), your user directory on Linux). Double click the main program (JCrypTool.exe on Windows, JCrypTool on macOS) to start the program.

JCrypTool is not signed for macOS, therefore the first start is a little bit different. After extracting JCrypTool click on it and select Open in the context menu. This will show a warning that JCrypTool is not signed by a verified developer. Click on Open in this dialog and enjoy JCrypTool. Following starts can be done as usual, e.g. by a double click. This signatur will be added in the release version.

All operating systems
JCrypTool only requires an installed Java Runtime Environment (JRE) or as an alternative a Java Development Kit (JDK) in version 1.8. In case no Java version is installed on your system, you can download the JRE for your platform for free at Oracle. JCrypTool cannot be launched without Java or with any Java version older than 1.8. The x64 version of JCrypTool requires an x64 Java Runtime Environment.

After the first start, the welcome page will show up. New users should read this short information; it presents some JCrypTool concepts and will make your first steps much easier.

Need help? Do you have trouble with the installation or your first steps? Discovered a bug or a problem? Feel free to ask a question in the JCrypTool Users and Developers Group.

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