Classic Cryptography: Holy Riddle

Classical Cryptography: Holy Riddle

This lab challenges you to uncover a hidden flag protected by an ancient cipher. As an analyst, you must interpret a riddle, apply classic cryptographic techniques, and validate your discovery in a secure environment.

In this lab you will learn:

• Identifying classic ciphers from subtle clues.
• Practical application of text transformations.

🌱 How to start this lab

👉 This challenge is validated from the brokendb virtual machine.

1. If you don't have it yet, download the virtual machine from this link:

1https://storage.googleapis.com/cybersecurity-machines/brokendb-lab.ova

1. Import the virtual machine into VirtualBox.
2. When you need to validate, start the VM and log in as user student:4geeks-lab.

Your mission

Your challenge begins with a riddle. Read it carefully, it contains clues about the cipher method used by the attacker to hide the true value of the flag.

Riddle

In a mirror you will find me,
what is A becomes Z, simply.
No key or number will you change,
but each letter you will see reversed.

I am old and easy to see,
though I seem a game, I will drive you crazy.

What am I?

Your task is to discover: Which cipher technique does it refer to? Then apply the corresponding method to reveal the original version of the flag.

Encrypted Flag

14Tvvph{Zgy4hs_15_1mxi3w1yoV_i1tsg???}

Numbers, underscores, and question marks have not been modified.

Validation

When you think you have the correct decrypted flag, validate your result inside the virtual machine by running the following command:

1validate-holy-flag

Observe the result. If your flag is correct, you will receive a message confirming you have successfully decrypted the Atbash cipher.

This lab is not just about decrypting text. It's about recognizing ancient patterns, applying reverse logic, and validating results precisely.

💡 Tip: The name of the challenge... is also a clue.

Good luck, Analyst!