VJC Chapter 27 Network Security

VJC/H2Computing/9569 Chapter 27 Network Security Content 1 Introduction to Network Security 2 Threats 2.1 Malware 2.2 Denial of Service (DoS) 3 Protection Mechanisms 3.1 Firewalls 3.1.1 Software and hardware firewalls 3.1.2 Host-based vs Network-based firewalls 3.1.3 Functionality and Structure of firewalls 3.1.4 Limitations to firewalls 3.2 Intrusion Detection System and Intrusion Prevention System 4 Secure access method 4.1 Encryption 4.2 Symmetric key encryption 4.3 Public key encryption 4.4 Digital signature 4.5 Authentication Annex 1 - What is the Internet of Things (IoT)? Annex 2 - Packet Sniffer Annex 3 - IP Spoofing Annex 4 - Security Tokens (Two-Factor Authentication) References Syllabus Learning Outcomes 4.3 Network Security Understand computer network security in terms of threats, protection mechanisms, and secure access. 4.3.1 Understand how malware (e.g. worms and viruses) and denial of service (DOS) attacks can compromise computer systems. 4.3.2 Understand how firewall (filtering function), intrusion detection system (IDS), and intrusion prevention system (IPS) can be used to restrict network access and their limitations. 4.3.3 Understand how encryption, digital signature, and authentication can ensure the security of network applications.

1 VJC/H2Computing/9569 1 Introduction to Network Security In today's digital world, our reliance on computer networks is undeniable. We use them for everything from online banking to social media, making them a prime target for malicious actors. This is where network security comes in. Network security is the shield that protects the confidentiality , integrity , and availability (CIA triad) of information and resources within a network. Confidentiality : This principle ensures that only authorised users can access sensitive information within the network. Think of it as keeping your secret documents locked away in a safe, accessible only to those with the proper key (authorization). Encryption and access controls are crucial for maintaining confidentiality. Integrity : This principle ensures that data within the network is accurate and hasn't been tampered with. Imagine working on a crucial report and someone changing the data without your knowledge. Intrusion detection systems (IDS) and digital signatures help guarantee the integrity of data by identifying unauthorized modifications. Availability : This principle ensures that authorised users can access the information and res