Welcome to CrypTool
CrypTool offers knowledge about cryptology and free tools to self-educate and to teach about cryptology.
Check out our projects
Play with cryptological tools online
CrypTool-Online (CTO) offers you many tools to experiment with concepts of cryptology. Ciphers, codings, cryptanalysis, and games. Easily in your browser.
Combine cryptological components
CrypTool 2 (CT2) is the successor of the famous CrypTool 1. You can use it to visually connect a whole range of cryptologic components to see how they work together and to build your own workflow.
Solve cryptological puzzles
MysteryTwister is an online contest that offers you cryptological puzzles. There are four levels: I is for beginners, II gets a little harder, III is really hard, and the solutions to X are mysteries! Find out.
Teach cryptology in school
Especially created for the 11th grade of Bavarian schools. Gives you a step-by-step introduction to codings and ciphers, with tasks to prove your understanding.
Learning course for 11th grade
Decipher historical manuscripts
George Lasry contributed a Java tool that you can use to transcribe and cryptanalyze historical encrypted manuscripts. For historians and linguists interested in cryptology.
The original CrypTool version
CrypTool 1 was the most widely used educational software in the field of cryptology. It has first been developed in 1998 at the security department of Deutsche Bank. And it's still used for awareness training today. Further development was discontinued in favor of CrypTool 2.
CrypTool on all major operating systems
JCrypTool is written in Java. It offers you many cryptological learning plugins. One focus are post-quantum signature algorithms. Further development has been discontinued, but JCT is still maintained.
CrypTool action days in schools
Take part in practical project days about cryptology at your school. If you're a teacher, feel free to contact us.
Read more about cryptology
Our project founder Prof. Esslinger wrote a book about cryptology. If you want to delve deeper into the subject, you will find many practical examples in it.
Find other crypto related websites
CrypTool participates in a chain of links through which you can discover more websites about cryptography:
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The CrypTool project is hosted, funded and supported by the Research Institute CODE. Thank you very much.
Thanks to all people and organizations who contributed to CrypTool over the years. If you want to contribute yourself, we're happy to read a message from you.