The development of CrypTool started in 1998. Originally developed by German companies and universities, it is an open-source project since 2001.[2]
Currently 4 versions of CrypTool are maintained and developed: CrypTool 1 (CT1), CrypTool 2 (CT2), JCrypTool (JCT), and CrypTool-Online (CTO). All are available in English and German.[3]
The goal of the CrypTool project is to make users aware of how cryptography can help against network security threats and to explain the underlying concepts of cryptology.[4]
The development of CT1 started in 1998. It is written in C++ and designed for the Microsoft Windows operating system.
In 2007, development began on two additional projects, both based on a pure-plugin architecture, to serve as successors to the original CT1 program:
CrypTool 2[5][6][7] (built with C#/.NET/WPF) (abbreviated CT2)
uses the concept of visual programming to clarify cryptographic processes. Currently, CT2 contains more than 150 crypto functions.
JCrypTool 1.0[8][9] (built with Java/Eclipse/RCP/SWT) (abbreviated JCT)
runs on Windows, macOS, and Linux, and offers both a document-centric and a function-centric perspective. Currently, JCT contains more than 100 crypto functions. One of its focal points are modern digital signatures (like Merkle trees and SPHINCS).
The browser software CrypTool-Online (CTO) has been in development since 2010 and is now the one most widely used.