Glossary
CTF (Capture The Flag)
A CTF is a cybersecurity competition where you solve challenges to find a "flag", a text string that proves you succeeded.
A CTF (Capture The Flag) is a cybersecurity game or competition. Each challenge hides a flag — a string like FLAG{...} — that you find by exploiting a flaw, decoding a message or analysing a file.
Classic categories: web, cryptography, reverse engineering, forensics… and hardware, where the challenge is a physical object: a board, a chip, a radio signal.
CTFs are used for learning and hiring. To practise on realistic systems, our sister platform CyberCTF offers pentest labs; for hardware, our hardware CTF puzzles are solved at home.