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.
Free Cryptography Course from Stanford Professor Dan Boneh
This course explains the inner workings of cryptographic functions and how to correctly use them. The course starts till end of March 2012 and will last at least 5 weeks. Normally, students have to work through the exercises in the same week the lessons are published.