Network Security


This lecture is an introduction to network security and its fundamental topics. We define security goals and threats and introduce firewalls and cryptographic operations. This knowledge is used further as a starting point for the design of secure networks. We present modern security protocols used in network protocols and architectures and vulnerabilities in existing systems. Lastly, the lecture provides an introduction to privacy in computer networks.

Lectures, Hacking Challenges, and Exercises


Lectures take place on Mondays from 12:15 - 13:45 and on Tuesdays from 14:15 - 15:45 in Hörsaal 2 of the Interimsgebäudes 1 (5620.01.102). The first lecture is on Tuesday, 17.10.2023.

Hacking Challenges and Exercises

Our lecture is accompanied by theoretical exercises and practical hacking challenges.

Exercise sheets are intended to deepen and supplement the understanding of the material discussed in the lectures. Exercise sheets will be handed out every one or two weeks and should be worked on as a homework – also gladly in teams. The solutions of the exercises will be discussed two weeks after their release in a central group exercise, which is part of a regular lecture slot. We strongly recommend that you actively work on the exercises and discuss their solutions with us. In addition to deepening the lecture material, the exercises also serve as good examples for exam questions.

Additional practical skills and a grade bonus can be acquired in the hacking challenges. You are supposed to attack and outsmart network services or security components specially prepared by us. For this purpose, Python or Bash scripts have to be written. If your hack is successful, you will receive a personalised token as a prize, which you can upload to a designated website together with the script you have written. After checking your script, you will receive points and be ranked on a leaderboard. The highest ranked student(s) will receive a "Best Hacker of the Year Award". In addition to fame and glory, your points also serve as a grade bonus in the end-term or retake exam.

For the hacking challenges, we suggest that students are already familiar with Python 3 (recommended reading: Python 3 Tutorial).

We will explain our exercise mode in greater detail in the introductory lecture on 17.10.2023.

Hybrid Teaching

We hold lectures and the central exercises on-site and provide a live stream and recordings ("video on demand") using RBG Live. You will find the streaming/recording URL in the lecture's Moodle course (see below).

For remote questions, feedback, etc., during lectures/central exercises, we use Tweedback - you will find the link in Moodle. Please be aware that the streaming platform causes a 20 - 30 second delay between you and the lecture hall. Hence, the lecturer might already discuss a different slide/topic when your question arrives in the lecture hall. We try to answer Tweedback questions on stage. If we cannot answer a question, we will answer it after the lecture in Moodle's "Course Discussion" forum. We also recommend that students that want to actively participate follow the lectures/central exercises on-site.

As explaining material yourself is the best way to check if you understood a topic, we want to encourage students to ask and answer questions about lectures/exercises in the dedicated "Course Discussion" forum on Moodle. We will moderate the threads to ensure that the given answers are correct and give answers if there are none.

Moodle Course

We publish lecture slides, exercise sheets, hacking challenges, links to RBG Live and Tweedback, and news and announcements in our Moodle course. The URL is


Registration for the lecture is possibele from 16.08.2023 - 13.01.23. Please note that you MUST be registered to the lecture if you want to participate in one of the examinations!

End-term and Retake Examination

There will be an end-term examination at the end of the lecture period (February) and a retake examination at the end of the lecture-free time (April).

For both exams, the following conditions apply:

  • Written exam, on-site
  • 75 minutes
  • Allowed tools: an analog dictionary English <-> Other Language without any remarks

We will announce the examination date/time and location on Moodle.