Challenge list
CryptographyLevel 1★☆☆☆☆02. Hidden Secret - Base64 Decode
Base64 is an encoding method used to transmit binary data as text. It's not encryption, but it's often used for…
Network SecurityLevel 1★☆☆☆☆08. Network Basics - Learn Port Numbers
Networks use port numbers to identify services. For example, a web server (HTTP) usually uses port 80, and encrypted…
CryptographyLevel 1★☆☆☆☆11. Decode the Caesar Cipher
The Caesar cipher is one of the oldest classical ciphers used by Julius Caesar. It encrypts by shifting alphabet…
Digital ForensicsLevel 1★☆☆☆☆12. Identify File Signatures
Files contain identification information called "magic bytes" at the beginning. Even if the extension is disguised,…
Digital ForensicsLevel 1★☆☆☆☆13. Hidden Metadata in Images
Photos and images contain metadata called EXIF. This metadata records shooting date, camera info, GPS coordinates,…
CryptographyLevel 1★☆☆☆☆14. ROT13 Magic
ROT13 (Rotate 13) is a type of Caesar cipher that shifts the alphabet by 13 letters. Interesting feature of ROT13:…
Digital ForensicsLevel 1★☆☆☆☆15. Extract Strings from Binary
Binary files (executables, etc.) contain human-readable strings. Passwords, URLs, error messages, and other hints can…