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.
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.
Third public beta of CrypTool 1.4.31
The new CrypTool 1.4.31 beta is ready. This version is now available in 6 languages German, English, Spanish, Polish, Serbian and Greek. We would appreciate if you test this beta in detail and give us feedback. The release version of CT 1.4.31 is scheduled for mid 2014. (2013-10-04)
Land der Ideen - Statements
"On the one hand, CrypTool has very efficient implementations including cryptanalysis and all relevant standards. So the tool is technically very useful. On the other hand, the visualization and presentation of the cryptographic techniques in CrypTool is excellent and there is no system that I know of that combines those two qualities in such an outstanding way."