Symmetric encryption (AES, DES) in Cybersecurity - Mini Project: Build & Apply

Symmetric Encryption Basics with AES and DES

📖 Scenario: You work in a small company that wants to protect sensitive messages. Your task is to understand how symmetric encryption works using AES and DES algorithms.

🎯 Goal: Build a simple explanation and example of symmetric encryption using AES and DES concepts to understand how the same key is used for both encrypting and decrypting messages.

📋 What You'll Learn

Create a dictionary with two encryption algorithms and their key sizes

Add a variable to hold a sample secret key

Write a loop to show how the same key is used for both encryption and decryption

Add a final note explaining the importance of keeping the key secret

💡 Why This Matters

🌍 Real World

Symmetric encryption is widely used to protect data in messaging apps, file storage, and secure communications where speed and efficiency are important.

💼 Career

Understanding symmetric encryption is essential for cybersecurity roles, software development, and IT professionals who implement data protection measures.

1

Create a dictionary of symmetric encryption algorithms

Create a dictionary called algorithms with these exact entries: 'AES': 256 and 'DES': 56, where the numbers represent the key sizes in bits.

Cybersecurity

# Create the dictionary algorithms with AES and DES key sizes
# Your code here

Need a hint?

Use curly braces to create a dictionary with keys 'AES' and 'DES' and their key sizes as values.

2

Add a secret key variable

Add a variable called secret_key and set it to the string 'mysecretkey123' to represent the shared key used in symmetric encryption.

Cybersecurity

algorithms = {'AES': 256, 'DES': 56}
# Add the secret_key variable below
# Your code here

Need a hint?

Assign the exact string 'mysecretkey123' to the variable secret_key.

3

Show encryption and decryption using the same key

Write a for loop using variables algorithm and key_size to iterate over algorithms.items(). Inside the loop, create two variables: encrypt_key and decrypt_key, both set to secret_key to show the same key is used for encryption and decryption.

Cybersecurity

algorithms = {'AES': 256, 'DES': 56}
secret_key = 'mysecretkey123'
# Write a for loop to assign encrypt_key and decrypt_key inside
# Your code here

Need a hint?

Use a for loop with algorithm and key_size to iterate over algorithms.items(). Inside, assign encrypt_key and decrypt_key to secret_key.

4

Add a note about key secrecy

Add a variable called note and set it to the string 'Keep the secret key safe to ensure secure communication.' to emphasize the importance of key secrecy in symmetric encryption.

Cybersecurity

algorithms = {'AES': 256, 'DES': 56}
secret_key = 'mysecretkey123'
for algorithm, key_size in algorithms.items():
    encrypt_key = secret_key
    decrypt_key = secret_key
# Add the note variable below
# Your code here

Need a hint?

Assign the exact string about key safety to the variable note.