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Tech for Good: 🕵️‍♀️ Decrypt the Secret Message Challenge

Mission Brief​

You're part of something big — a Tech for Good mission. Somewhere, hidden across the web, are clues to unlock a powerful message.

You’ll need to:

  • Hunt for 3 secret flags 🏁
  • Combine them into a 🔑 decryption key
  • Use CyberChef to 🔓 unlock the message

🔍 Find the 3 Hidden Flags​

Each flag looks like this:


FLAGX{someword}

Explore these sites carefully, find the flags:

  • 🛰️ https://www.pasifikateched.net/ hint: have a look at the Tech Workshop page source...
  • ⚡ https://technesianlivestream.github.io/docs/ hint: so many cool episodes! Ep4 looks interesting...
  • 🧠 https://www.theuncommon.ai/ hint: robots.txt

Write down each flag but rememeber the order!!

Then, strip the FLAGX{} part and combine the words in order:

FLAG1, then FLAG2, then FLAG3.

e.g. if your 3 flags were: FLAG1{tech}, FLAG1{for}, FLAG1{good}

your decryption key would be 'techforgood'

🔐 Decrypt the Message in CyberChef​

Go to CyberChef and follow these steps:

  1. Look at the left-hand-side Menu, click "Encryption/Encoding".
  2. Drag & Drop "AES Decrypt" to the "Recipe" section

CyberChef-AESDecrypt-1

  1. Set the recipe settings to the following (drop-down menus):
  2. Key: your secret decription key goes here, set to UTF-8
  3. IV: paste this in the input box 1234567890abcdef, set to UTF-8
  4. Mode: CBC
  5. Input: Hex
  6. Output: Raw

your setup should look like this:

CyberChef-AESDecrypt-2

🔓 Decryption Time!​

Copy & Paste the key you got from putting the 3 Flags together e.g. techforgood into the Key input box.

Now, copy & paste this cipher text into the Input box to the right of the Recipe box...

Encrypted Text

f8b61164367c7abcf793d89b001dbbc12ebce00d59b851f2b44ae0502b251e7544b6eefb2ccd1df53dd956c648fd942b4bbe1aeb015f455c8016caa06231c2130af08c41b3755d88f57157a121d4d146988bab1b1f9577b17e91903f5848ea2391a65642e91cc466d56c7ed3a8e6cafc280ba12779ba589873f2fad8dbbc67e7be12a46de0e024b0beeaa6b765a1bb9bc7382b5255e943648dbbd43170d90183

If you’ve got the correct key — boom! 🎉 You’ll see the decrypted message in the Output box.

CyberChef-AESDecrypt-2

🏆 Bonus Questions​

  • What does AES stand for?
  • Why do we need an IV?
  • What are ways real hackers hide clues in webpages?
tip

✅ You Win When​

You’ve decrypted the message and can explain how you found the flags.

Cyber skills + curiosity = unstoppable.

🌊 Keep building. Keep believing.