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.
CT 2.0 released
The release version of CrypTool 2.0 was released on 20th Aug 2014. We would be happy if many of you use it for teaching, self-study, education and awareness and give us feedback. (2014-08-25)
Article about solving the Double-Transposition Challenge in Cryptologia
A level X challenge in MysteryTwister C3 by Klaus Schmeh using the double-column transposition cipher withstood a long time against cryptanalysis efforts. Nevertheless, it was solved in November 2013 by George Lasry. (2014-06-25)
The 10th Beta of CrypTool 2 was released on 19th October 2013. You are cordially invited to test and give feedback. Final version of CT 2 is planned to be published in July 2014.
Land der Ideen - Statements
"Thanks a lot for the release of CrypTool, which is an excellent tool for teaching cryptography. As for the feedback from the students, I would like to mention that I haven't had any complaints about CT. Generally, students are very positive about the tool and we are certainly continue to use it in our lab."