Cyber Security (Copy)
IGCSE / O Level Computer Science Cheat Sheet
Topic: 5.3 Cyber Security
🔐 What is Cyber Security?
- Cyber security is the protection of computer systems, networks, and data from unauthorized access, damage, or theft.
🚨 Common Cyber Security Threats
| Threat Type | Description |
|---|---|
| Brute-force attack | Repeatedly tries different passwords to gain access |
| Data interception | Capturing data in transit without authorization (e.g. packet sniffing) |
| DDoS attack | Overloads a server with traffic from multiple sources to disrupt service |
| Hacking | Unauthorized access to or manipulation of data/systems |
| Malware | Malicious software (viruses, worms, trojans, ransomware, spyware, adware) |
| Pharming | Redirects users to fake websites to steal information |
| Phishing | Fraudulent messages/emails tricking users to reveal personal data |
| Social engineering | Manipulating people into giving up confidential information |
🛡️ Cyber Security Solutions
| Method | Description |
|---|---|
| Access levels | Restrict data access based on user roles |
| Anti-malware software | Detects and removes malicious software (e.g. antivirus, anti-spyware) |
| Authentication | Verifies user identity using passwords, biometrics, or 2FA |
| Firewalls | Monitors and blocks unauthorized network traffic |
| Automated updates | Keeps software up-to-date to patch vulnerabilities |
| Proxy servers | Acts as intermediary for requests; can block or filter traffic |
| SSL (Secure Socket Layer) | Encrypts data during transmission (used in HTTPS) |
| Privacy settings | Controls what information is shared or stored |
🔁 Authentication Methods
| Method | Description |
|---|---|
| Username + Password | Common method; can be vulnerable |
| Biometrics | Fingerprint, retina scan, facial recognition |
| Two-step verification (2FA) | Adds second authentication layer |
📧 Phishing and Pharming Prevention
| Check | Purpose |
|---|---|
| Spelling and tone in messages | Detect suspicious content |
| Check URL of links | Avoid fake or redirected sites |
🔁 Summary Table
| Threat | Example | Solution |
|---|---|---|
| Phishing | Fake email from “bank” | Ignore, report, use 2FA |
| Malware | Keylogger records passwords | Use antivirus software |
| DDoS Attack | Website slowdown | Use firewall and traffic filters |
| Data Interception | Unsecured public Wi-Fi | Use SSL encryption (HTTPS) |
| Brute-force Attack | Password guessing | Lockout systems, use strong PWs |