This preliminary course is a voluntary offer from the Chair of IT Security. The course and its contents are subject to change without notice. The course is neither graded nor credited and is not an official part of the master programme Cyber Security. Thus, there will be no registration in the Registrar's Office. All necessary materials will be provided on Moodle.

In this voluntary course, we will revise basic mathematical methods, assumed to be known by master students in Cyber Security. Therefore, we will discuss the following topics:

• Sentential logic and naive set-theory
• The definition of the natural numbers and the induction principle
• Basic principles of proving theorems
• Equivalence relations
• Introduction to groups, rings, and number fields
• Basics of solving linear equation systems
• (extended) Euclidean algorithm
• Chinese remainder theorem and its applications

While covering these topics, we will take a special focus on the residue class ring on integer numbers, which plays an important role in basic cryptographic algorithms such as RSA.