Free, always
No locked lessons and no premium tier for the good parts. Knowledge here is open.
Free lessons in a clear order. Each module ends with a small practice flag.
Learning for everyone was the first thing CTF ORION stood for. It still decides how lessons are built and who they are for.
No locked lessons and no premium tier for the good parts. Knowledge here is open.
No deadlines and no streaks. Come back after a week or a year and pick up where you stopped.
Foundations assumes nothing. If you can use a browser, you can start today.
Lessons come from the community too. Learn here today, teach here tomorrow.
Ten modules from no background to your first full challenge. Do them in order; each one builds on the last.
After Foundations, go deeper in the area you enjoy most. Each path matches a challenge category, so practice is always one click away.
From classical ciphers to how modern schemes break when they are used carelessly.
File formats, disk images and network captures, and how to find what someone tried to hide.
Reading programs you did not write: assembly basics, decompilers and patient note-taking.
Searching public sources carefully, verifying what you find, and respecting the people behind the data.
Messages tucked inside images, audio and documents, and the tools that bring them out.
These paths open together with machine-based challenges, once our tunnel system is ready.
Every module, in every path, follows the same three steps.
Short pages with diagrams and examples. Most take ten to twenty minutes.
A guided exercise with a downloadable file, so you practise on something real.
Paste the flag you found. Lesson flags add their points to your place on the learner board.
Write a module or a whole path. Community lessons are reviewed and published with your name on them.