13 TOPICS · 89 CHALLENGES · SELF-PACED
CTF foundations
Learn capture-the-flag from zero: encodings, crypto, web, forensics, networks, OSINT, reversing and more. Every challenge runs in your browser with its evidence supplied. Sign in to submit flags and save your progress.
- What is a CTF?Jeopardy vs attack-defence, flag format, scope, teams and the ethics pledge. · 6 flags
- CTF essentialsFind evidence, recognise a flag, search instead of scroll, and keep notes. · 6 flags
- Encodings and bytesBase64, base32, hex, binary, decimal, octal, URL encoding and layered encodings. · 9 flags
- Linux and the terminalHidden files, grep, find, permissions, pipes and strings on the command line. · 6 flags
- Introductory cryptographyROT13, Caesar with an unknown shift, and the Atbash mirror cipher. · 6 flags
- Ciphers, hashes and keysVigenere, known-plaintext attacks, hashes, Morse, tiny RSA, encoding vs encryption. · 6 flags
- Web inspectionView source, cookies, hidden fields, robots.txt, IDOR and reading a JWT. · 9 flags
- Artifact forensicsMagic bytes, metadata, nested archives and data hidden after a file's end. · 7 flags
- Network evidenceReading HTTP by hand, DNS TXT records and following a TCP stream. · 8 flags
- OSINT (fictional targets)Reused handles, photo geolocation and web archives - on invented people only. · 6 flags
- Reversing fundamentalsReading a check, strings built at runtime, and undoing a single-byte XOR. · 8 flags
- Scripting for CTFsScript repetitive decoding: shifts, brute-forcing a Caesar, repeating-key XOR. · 6 flags
- Mini CTF: put it togetherMulti-step challenges that chain web, forensics, crypto, networks and OSINT, then a write-up. · 6 flags