Lecture: Network Security

You want to know how today’s attacks against networks work? You want to learn about countermeasures and how to secure your network? Then this is your lecture! The lecture introduces actual threats on and attacks against computer networks (e.g. worms, bot-nets). You will gain a practical insight into their functioning and damage potential. During the lecture, you will be hacking systems yourself, but also learn about security protocols and state-of-the-art defense measures, including Intrusion Detection Systems and Honeypots. So, if you are interested in network security and willing to work, we would be happy to see you in the first lecture.




  • Term: Master Computer Science, Diploma (Graduate)
  • Requirements: Content of "High Performance Networking" is prerequisite. Basic programming skills (see below).
  • Faculty: MA-INF 3201; Media Informatics; old DPO: B,C; new DPO: B
  • Effort: 2.0 L + 2.0 E / 6CP(MA); 4CP(B-IT MI); 4CP(Diplom)
  • Follow-up/Side-events: A seminar will take place at the end of the lecture period. Subsequent to lectures "Data Communication and Internet Technology" and "Network Security" participating in a lab is possible.


There will be no lecture in the first week! The first lecture will be held on Thu, 17.04.2013. The first exercise will be held on Thu, 24.04.2013!


Required Programming Skills

The lecture Network Security teaches security from a very practical point of view. This includes hands-on exercises, hacks and the development of countermeasures. For students participating in the lecture it is mandatory to have basic programming skills. We are providing a self-test, which shows the level of your skills and tells you if you are capable to deal with the practical tasks.

Application for an account in the Network Security Lab

Please see "Information on Tutorials/Exercises" below.

Slides and Presentations

Access to the files requires a username and a password. Both will be announced in the first lecture.


0 – Preface

undefinedSlides 1-23

1 – Introduction

undefinedSlides 1-24

2 – Attack Overview

Protocol Attacks

  • TCP Refresher
  • Session Hijacking
  • TCP DoS Attacks
  • The RST Attack
  • DNS Spoofing


undefinedSlides 1-35

3 – Attack Vector SQL Injection


undefinedSlides 1-19

4 – Cryptography

  • Encryption
    • symmetric, asymmetric, hybrid encryption
    • stream ciphers, block ciphers
  • Integrity Protection
    • Hash functions
    • HMAC
  • Authentication
    • Certificates
    • Certificate Authorities
  • Application: PGP


undefinedSlides 1-74

5 – Building Secure Channels

Authentication and Encryption

  • Authentication and Encryption
  • Authenticated Encryption Schemes
  • CBC Weakness
  • Security of Authenticated Encryption Schemes

Key Management

  • Common Threats for Key Exchange
  • Countermeasures
  • Key Hierarchy
  • Attacks on Protocols


undefinedSlides 1-27

6 – Authentication

Authentication Protocols

  • Authentication Overview
  • Basic Authentication Protocols

Authentication Frameworks

  • EAP and IEEE 802.1x
  • Application to WLAN Security


undefinedSlides 1-43

7 – Network Infrastructure

Network Infrastructure and Management

  • Network Management Concepts
  • SNMP

Layer 2 Security

  • Layer 2 Overview
  • Spanning Tree Operation and Security
  • VLAN Concepts and Management
  • VLAN Security
  • ARP, DHCP Security


undefinedSlides 1-34

8 – Firewalls


undefinedSlides 1-41

9 – Malware spreading

  • Ways to infect computers with malware
  • Internet Worms: History and Examples
  • Social Engineering
  • Drive-by downloads
undefinedSlides 1-66

10 – Botnets

undefinedSlides 1-17

11 – Attack Vector Buffer Overflow

undefinedSlides 1-37

Assignment Sheets

The PDF files can be viewed and printed with Adobe Reader. The program is undefinedavailable for free and installed on nearly all hosts of the institute.

Information on Tutorials/Exercises: undefinedPresentation [PDF] from 17.04.2014

Information on "SecLab", our security laboratory: undefinedInfo sheet [PDF]

Publication DatePDF FileSupplementary MaterialSubmission DeadlineScheduled ExerciseHandout
24.04.2014undefinedAssignment Sheet 1undefinedattack-trace.pcap06.05.2014 23:59:59 CEST08.05.2014 15:00n/a
08.05.2014undefinedAssignment Sheet 220.05.2014 23:59:59 CEST22.05.2014 15:00undefinedExercise Meeting 2
22.05.2014undefinedAssignment Sheet 3
undefinedsniffer.py03.06.2014 23:59:59 CEST05.06.2014 15:00
05.06.2014undefinedAssignment Sheet 417.06.2014 23:59:59 CEST18.06.2014 15:00
19.06.2014undefinedAssignment Sheet 501.07.2014 23:59:59 CEST03.07.2014 15:00
07.07.2014undefinedAssignment Sheet 6none, sheet is voluntary17.07.2014 15:00