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 the last few years, CrypTool has become to an indispensable part of my lectures in IT security. Due to its broad concept, the clear structure, and the explicatory and illustrative character, the software is suitable both for the lecturer's presentations and the student's self learning. CrypTool is very stable and consistent."
Professor Roßbach, Frankfurt School of Finance and Management
RSA sanity check
Testing RSA moduli for shared prime factors. Full article (2012-05-24)