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.
“The freely-available demonstration program CrypTool is highly recommended for practical exercises.”
Wolfgang Ertel, Vorwort in "Angewandte Kryptographie"
Portal for teachers
For teachers who want to introduce their pupils into the fascinating world of cryptography the CrypTool project started the Cryptoportal for teachers (only german). On this portal teachers could exchange learning material and have a discussion about it.