CrypTool-Online (CTO) runs in a browser and provides a huge variety of encryption methods and analysis tools including many illustrated examples.
The CODEBREAKERS.EU cryptology game -- 4th edition
On June 1st, 2015 begins a "fantastic game" starting with the 1st of six tasks on the Enigma level. The material to be studied is published twice a week, but the time in which you work out the final tasks matters the most. (2015-06-01)
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)
"In addition to the appealing appearance and the extensive scope of operation, the team of CrypTool developers must also be praised. Wishes regarding missing functionality or suggestions for improvement are always promptly acted on and, where possible, integrated into new versions. In addition, the path chosen for recent developments is in my opinion a great success: Especially the building-block design with the independent modules (e.g: encryption, hashes or signature) that can be combined in activities, will be an inspiration for students.”