Course overview

Your roadmap to network security.

Twenty modules across five chapters, available in three difficulty tracks. Pick a track below and start with the first module. Switch tracks any time, your XP travels with you.

1. Choose your track

Same topics, three depths. You can change this on the Modules page later.

2. The five chapters

Each chapter builds on the previous one. You can jump ahead, but the suggested order keeps mental load low.

  1. Chapter 1

    Foundations

    What does it mean for a system to be secure? The CIA triad, threat models, the attacker mindset, and the legal and ethical lines you should never cross.

    3 modules · CIA triad · Threat models · Ethics & law

  2. Chapter 2

    Cryptography

    The tools that make modern communication trustworthy: symmetric and asymmetric encryption, hashing, message authentication codes, digital signatures, certificates, and TLS.

    4 modules · Symmetric · Asymmetric & PKI · Hashing & MACs · TLS

  3. Chapter 3

    Authentication & Access

    How systems decide who you are and what you may do: passwords, multi-factor authentication, sessions and tokens, OAuth, and OS-level access control.

    4 modules · Passwords · MFA · Sessions & OAuth · OS access control

  4. Chapter 4

    Network Security

    The internet layer by layer: TCP/IP refresher, sniffing and spoofing, MITM attacks, firewalls, IDS/IPS, VPNs, and Wi-Fi security.

    4 modules · Networking refresher · Attacks · Defenses · Wireless

  5. Chapter 5

    Attacks & Defenses

    The classics that still cause incidents today: OWASP Top 10 web vulnerabilities, malware families, social engineering, privacy and anonymity, and incident response.

    5 modules · Web · Malware · Social engineering · Privacy · IR

3. How a module works

Every module follows the same loop. Predictable structure, less friction.

Step 1

Read

10 to 20 minutes. Clear objectives at the top, key takeaways at the bottom, glossary links throughout.

Step 2

Quiz

3 to 5 questions to confirm the concept stuck. Hints available at a cost. Pass = 70%.

Step 3

Play

Where it makes sense, a mini-game gives you hands-on practice with the same idea.

Step 4

Earn

XP, level-ups, and badges. Or ignore them, modules read fine without the gamification.

FAQ

Where is my progress stored?

In your browser's localStorage. There is no account, no server, no tracking. To move between devices, export your progress as JSON on the Progress page and import it on another device.

Do I have to stay on one track?

No. You can switch tracks at any time on the Modules page. The track only changes the depth of each module, your XP and badges carry over.

Can I use this on mobile?

Yes. Modules, quizzes, and games are designed to work with touch and a small screen.

Is this a real course?

It's a self-paced learning site, not a university course. The depth at the Advanced track is comparable to an undergraduate Computer and Network Security class.

Is the source available?

Yes. The site is open source. Code is MIT-licensed; written content is CC BY-SA 4.0.

Ready when you are.

Pick a track above, then jump into the modules.

Browse modules