The Cyber Security Challenge Germany (CSCG) is the German hacking
competition for pupils and students. There are 12 online challenges
starting on May 2nd, 2016. The juveniles have to solve different
IT-Security tasks till August.
"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)