Capture The Flag(CTF) are computer security/hacking competitions which generally consist of participants breaking, investigating, reverse engineering and doing anything they can to reach the end goal, a “flag” which is usually found as a string of text.

A CTF is a system of increasingly-difficult challenges that can’t be too easy or too hard. A well-designed CTF teaches all of the participants stuff that they didn’t know, no matter how far they get and what skills they came in with. Designing a good CTF is difficult.

CTF’s are a competition. Organizing CTF’s involve the following:

• Registering teams
• providing login pages
• building the systems

With Facebook open-sourcing their CTF-hosting platform, along with a few starter challenges. Anyone can now host CTF’s with minimal effort.

CTF Time is another great resource to find archived CTF’s and other related information.

Links:

Facebook CTF Github
CTF Resources
CTF Time