Security missions

Think like an attacker. Work like a defender.

Short, legal ethical hacking challenges that run on this site only. Decode, investigate a log, review code, find the hole. Each mission checks your answer and explains the lesson behind it.

  1. 1Decode the message
    A beginner security mission: recognise and decode Base64, the encoding you will meet everywhere.
  2. 2The rotated note
    A classic cipher mission: crack a ROT13 message by shifting letters.
  3. 3Read the log
    A defensive security mission: find the attacker in a server login log.
  4. 4Spot the hole
    A code review mission: find the login bug that lets anyone in without a password.
  5. 5The AI wrote this
    An AI-era security mission: find the vulnerability in AI-generated database code.
  6. 6Hidden in plain sight
    A web security mission: find a secret left in a page's source code.

Practise only on these missions and on systems you own or have written permission to test. Anything else is illegal.