Welcome to CrypTool

This is the homepage of the CrypTool project. The CrypTool project consists of the e-learning software CrypTool 1, CrypTool 2, Java CrypTool and CrypTool-Online and the crypto puzzle contest MysteryTwister.

Our goal is to generate interest in crypto techniques in a playful way, thus providing easy access. You can experiment with crypto tools, learn cryptography and solve puzzles.

CrypTool-Online (CTO)

Play around with different cryptographic algorithms directly in your browser. For PC and mobile. No download needed.

CrypTool 1 (CT1)

Experiment with different cryptographic algorithms on Windows (started in 1998, unmaintained now). Download needed.

CrypTool 2 (CT2)

Visual programming, cascards of cryptographic procedures, and lots of cryptanalysis methods. Runs on Windows.

JavaCrypTool (JCT)

Runs on Linux, macOS and Windows. One focus are post-quantum signature procedures.

MysteryTwister (MTC3)

International crypto cipher challenge, offering cryptographic riddles of 4 levels.

Scholar Crypto (SCR)

Learn/teach cryptography at your school. We sometimes organize practical project-days with your teachers. Feel free to contact us.

Through the support of universities and research projects, we can offer you everything here free of charge.

If you would like to participate yourself, please feel free to write us a message.