Learn how the internet defends itself.
A gamified course in computer and network security, from first principles to real-world attacks and defenses. Read short modules, play hands-on games, earn XP, and track your progress.
Three tracks. One foundation.
Same curriculum, three depths. Switch tracks any time, your XP comes with you.
Beginner
Plain-language explanations with everyday analogies. No prior CS background needed.
- Concepts and threat models
- Visual demos, no math
- Light, friendly quizzes
Intermediate
Mechanics, protocols, code snippets. Expects some programming and networking basics.
- Hands-on with crypto and TLS
- OWASP Top 10 in depth
- Real packet captures and CVEs
Advanced
Math, RFCs, case studies. For learners targeting research, red-team, or security engineering.
- Cryptographic constructions
- Exploit primitives and mitigations
- Capstone challenges
Built to make security stick.
Short, focused modules
Each topic is a 10 to 20 minute read with clear learning objectives, key takeaways, and a self-check quiz.
Hands-on mini-games
Spot a phishing email. Crack a Caesar cipher. Order firewall rules. Concepts become muscle memory.
XP, levels, and badges
Earn points for finishing modules, passing quizzes, and beating games. Visible progress, never forced.
Open and private by design
No login. No tracking. Your progress lives in your browser. Export it as JSON to move between devices.
Five chapters, twenty modules.
A complete arc from the basics of trust and threat modeling through cryptography, networks, web attacks, malware, and privacy.
Foundations
CIA triad, threat models, attacker mindset, ethics and law.
Cryptography
Symmetric and asymmetric encryption, hashing, MACs, TLS and PKI.
Authentication & Access
Passwords, MFA, sessions and OAuth, OS access control.
Network Security
TCP/IP, sniffing, MITM, firewalls, IDS, VPNs and wireless.
Attacks & Defenses
Web (OWASP Top 10), malware, social engineering, privacy, incident response.
All modules →
Browse the full module index.
Ready to start?
Open the overview, pick a track, and earn your first badge in under ten minutes.
Start the course