Welcome to CrypTool

Here you can try crypto tools, learn cryptography and solve puzzles. Our goal is to create interest in crypto techniques, raise awareness, and provide easy access.


Actively developed projects

CrypTool-Online (CTO)

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

CrypTool 2 (CT2)

Visual programming, cascades of cryptographic procedures, and lots of cryptanalysis methods. Download for Windows.

MysteryTwister (MTW)

International crypto cipher challenge, offering cryptographic riddles of 4 levels. Joint work of CrypTool and the University of Bochum.

CrypTool Transcriber & Solver (CTTS)

Java-based tool for transcription and cryptanalysis. Especially for encrypted historical documents.


Projects with maintenance



The CrypTool project started in 1998 as a training project for IT employees of Deutsche Bank AG and developed the e-learning software CrypTool 1.

Over the years, CrypTool 2 and JavaCrypTool were added, the crypto puzzle contest MysteryTwister and the web application CrypTool-Online. Also the CrypTool Book.

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

If you would like to take part yourself, you are welcome to send us a message.


Powered by CODE

The CrypTool project is hosted, funded and supported by the Research Institute CODE. Thank you very much.


Find other crypto related websites

CrypTool participates in a chain of links through which you can discover more websites about cryptography. Click:

Crypto Tour

Click these icons to discover other related sites