Security in Computer Networks Code:  22.627    :  6
View general information   Description   The subject within the syllabus as a whole   Professional fields to which it applies   Prior knowledge   Information prior to enrolment   Learning objectives and results   Content   View the UOC learning resources used in the subject   Additional information on support tools and learning resources   Guidelines on assessment at the UOC   View the assessment model  
This is the course plan for the second semester of the academic year 2022/2023. To check whether the course is being run this semester, go to the Virtual Campus section More UOC / The University / Programmes of study section on Campus. Once teaching starts, you'll be able to find it in the classroom. The course plan may be subject to change.

This course presents the security problems and solutions in computer networks, and more specifically in TCP/IP networks.

The structure of the course is as follows. First, we make a general introduction to cybersecurity, where we briefly review some of the main security problems in different systems (networks, operating systems, web, etc.). Secondly, we focus on network security and study prevention mechanisms, basically firewalls, and intrusion detection systems. Finally, we introduce basic notions of cryptography, and we study how to protect communication protocols and applications.

Students following this course need to take into account that the course requires a basic knowledge of how to work with TCP/IP networks and the GNU/Linux environment. Additionally, the course has a practical focus, which implies that students must have a computer with the minimum requirements described below, and have to devote some effort to the installation and configuration of software, and to the resolution of activities in this environment.


Before enrolling Security in Computer Networks it is recommendable to pass the course Network and Internet Applications.


The content of this course is aimed at developing the minimum skills required from professionals working as computer networks administrators or security officers. Nowadays, it is not possible to conceive of a network expert who does not have some basic notions of security.


The necessary previous knowledge to enroll on this course is:

  • Understanding the basic concepts of computer networks and TCP/IP.
  • Having some basic experience with GNU/Linux systems.


IT requirements

In order to solve the practical assignments of this course, it is necessary to have a computer that can smoothly run virtual machines in VirtualBox.


Specific competencies of this course

CE2: Understand and use the scientific bases of software development to analyse each problem at the appropriate level of abstraction and apply the skills and knowledge acquired in order to solve them.

CE5: Understand the fundamentals of operating systems and computer networks so as to design and develop solutions that take into account each platform's specific features, available and shared resources, and the system's security.

CE9: Propose and evaluate different technological alternatives for solving a specific software development problem.


Introduction to computer security

  • Security and risks
  • Computer attacks
  • Computer defence and security

Firewall systems

  • Types of firewall systems
  • Implementation of perimeter security through firewall systems
  • Iptables

Intrusion detection systems

  • Cyber defense and intrusion detection tools
  • Event, alert and incident management
  • Snort

Security in the communication layer

  • Link level protection: wireless networks
  • Network level protection: IPsec
  • Transport level protection: TLS

Security in the application layer

  • SSH
  • VPN
  • Secure e-mail

This course also offers basic content on encryption and authentication to allow students without previous knowledge of cryptography to follow the course.

Finally, in the course activities, students have to use tools to reinforce in a practical way the theoretical content. Some of these tools are:

  • Nmap
  • Wireshark
  • Iptables
  • Openssl
  • SSH
  • Snort
  • Nessus


Fundamentals of encryption and authentication PDF
Security in the communications layers PDF
Security in the application layer PDF


The didactic material of the course consists of 6 theoretical modules and 2 additional modules focused on the practical assignments. All modules are offered in digital format.

In certain sections of the course, if deemed necessary, supplementary material of special interest will be provided.


The assessment process is based on the student's personal work and presupposes authenticity of authorship and originality of the exercises completed.

Lack of authenticity of authorship or originality of assessment tests, copying or plagiarism, the fraudulent attempt to obtain a better academic result, collusion to copy or concealing or abetting copying, use of unauthorized material or devices during assessment, inter alia, are offences that may lead to serious academic or other sanctions.

Firstly, you will fail the course (D/0) if you commit any of these offences when completing activities defined as assessable in the course plan, including the final tests. Offences considered to be misconduct include, among others, the use of unauthorized material or devices during the tests, such as social media or internet search engines, or the copying of text from external sources (internet, class notes, books, articles, other students' essays or tests, etc.) without including the corresponding reference.

And secondly, the UOC's academic regulations state that any misconduct during assessment, in addition to leading to the student failing the course, may also lead to disciplinary procedures and sanctions.

The UOC reserves the right to request that students identify themselves and/or provide evidence of the authorship of their work, throughout the assessment process, and by the means the UOC specifies (synchronous or asynchronous). For this purpose, the UOC may require students to use a microphone, webcam or other devices during the assessment process, and to make sure that they are working correctly.

The checking of students' knowledge to verify authorship of their work will under no circumstances constitute a second assessment.


This subject can only be passed through a continuous assessment. The final mark on the continuous assessment will be the final mark for the subject.The subject's accreditation formula is as follows: CA