Communication Technologies Grade 12
This page focuses on how data is kept safe as it travels across a network — VPNs, encryption, digital certificates and authentication. For network hardware, internet access technologies and general remote access, see Networks & Remote Access.
T3Term 3 · VPNs, Encryption & Secure Communication
VPN — Virtual Private Network
A VPN creates an encrypted tunnel over the Internet, allowing secure remote access to a private network. (See Networks & Remote Access for the armoured-van analogy and a worked example.)
- Hides your IP address and location
- All data is encrypted — safe on public Wi-Fi
- Used by companies for remote workers to securely access internal systems
Encryption & Security
| Concept | Description |
|---|---|
| Encryption | Converts readable data into unreadable code. Only someone with the correct key can decrypt it. |
| SSL/TLS | Protocol securing communication between browser and server (HTTPS). Uses public/private key pairs. |
| Digital certificate | Issued by a trusted Certificate Authority. Verifies the website is legitimate. |
| Firewall | Filters incoming and outgoing traffic based on security rules |
| MFA | Multi-Factor Authentication — requires password + second factor (OTP, fingerprint) |
| OTP | One-Time PIN — valid for one login only; prevents replay attacks |
Email & Messaging Security
| Concept | Description |
|---|---|
| Spam filtering | Automatically detects and quarantines unsolicited/junk email before it reaches the inbox |
| Email encryption | Encrypts the message content so only the intended recipient's key can decrypt and read it |
| End-to-end encryption | Used by apps like WhatsApp/Signal — only the sender and recipient can read the message, not even the service provider |
| Digital signature | Confirms a message really came from the claimed sender and was not altered in transit |