Know and understand privacy and confidentiality of data transfer

4 Networks and the Effects of Using Them 📡

In this section we explore how different networks work, why privacy matters, and how data can stay confidential while travelling across the internet.

What is a Network?

Imagine a network as a giant post office system where messages (data) are sent from one person (device) to another. The post office can be local (like a school Wi‑Fi) or global (the internet).

Types of Networks

• Local Area Network (LAN) – your school’s Wi‑Fi
• Wide Area Network (WAN) – the internet
• Virtual Private Network (VPN) – a secret tunnel inside the internet
• Wireless Sensor Network (WSN) – tiny devices that share data wirelessly

Why Privacy & Confidentiality Matter

When you send a message, you usually want only the intended recipient to read it. If anyone else can see it, that’s a privacy breach.

Confidentiality means keeping information hidden from unauthorized users. It’s like putting a lock on a diary.

How Encryption Protects Data 🔒

Encryption turns readable data (plaintext) into unreadable code (ciphertext). Only someone with the right key can reverse the process.

Mathematically we can write it as:

$C = \text{Enc}(M, K)$

where M is the message, K is the key, and C is the ciphertext.

Common Threats to Privacy ⚠️

1. Man‑in‑the‑Middle (MITM) attacks – an attacker intercepts and possibly alters messages.
2. Packet sniffing – capturing data packets as they travel across a network.
3. Phishing – tricking users into revealing passwords.
4. Malware – software that can steal or encrypt your data.

Remember the Analogy!

Think of data as a letter you send. A LAN is like sending the letter within your school, where only classmates can see it. A WAN is like mailing it across the world, where anyone could intercept it unless you put it in a sealed envelope (encryption) and add a signature (digital signature) to prove it came from you.