Overview

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The security of computer networks is a key element in cyber security. Computer networking provides the foundational connectivity services that are used for the world wide web, distributed computer applications and services, operations and manufacturing, and national infrastructure. This course provides understanding of key technologies used in computer networks and infrastructure. This includes protocols, computer networks, data centres, operational technologies that form key infrastructure critical to the success of organisations and services from a local to an international scale. The course discusses vulnerabilities and the exploits that target computer networks, systems, and the Internet infrastructure. By the end of this course learners will be able to: 1. Show a systematic understanding of digital networks and their operation, including the OSI 7 layer architecture and the TCP/IP protocol stack. 2. Discuss key security threats and risks faced in computer networks. 3. Demonstrate a critical understanding of network security architecture and design rationale of selected protocols, security technologies and how they are used in practice. 4. Identify attack models and analyse vulnerabilities in protocols, network systems, and applications. 5. Demonstrate how these vulnerabilities may be exploited in practice to penetrate a system.

Syllabus

Introduction to the course and computer networks

In the first week, we will obtain an overview of the course and, in particular, get an overview of communication principles in networks as well as its threats. You will also reflect on your own expectations of what the course will teach. The key concepts for this week are messages, channels and network adversaries.

Network layers

In this week, we will take an in-depth look into the concept of network layering. Furthermore, we will discuss how network communication is performed with lower-layer network technology, such as Ethernet.

The internet protocol

In this week, we will explore the Internet Protocol (IP) that enables communication across several networked systems. We will discuss how IP builds upon the data-link network layer, how IP addresses can be assigned, and how messages can be forwarded.

Large-scale IP networks and message transport

In this week, we will conclude our exploration on the Internet Protocol (IP) that we have started last week. We will discuss how IP operates on a large-scale level and forms the global Internet. Furthermore, we will discuss how we can address messages to applications running on the same system and using the same IP address.

Data streams and application protocols

In this week, we will continue our discussion of the transport layer and learn about the Transmission Control Protocol (TCP). Furthermore, we will learn how applications communicate with each other using application protocols.

Secure communication

In our final week, we will see how we can build secure channels that aim for confidentiality and integrity. We will take a closer look at how the widely-used protocol transport layer security (TLS) constructs such channels.