Question

Given the following code for AES Electronic Code Block implementation for the encryption functionality. Modify the code to create a function named ‘encryptECB(key, secret_message)’ that accepts key and secret_message and returns a ciphertext.

         #Electronic Code Block AES algorithm, Encryption Implementation
from base64 import b64encode
from Crypto.Cipher import AES
from Crypto.Util.Padding import pad
from Crypto.Random import get_random_bytes
secret_message = b" Please send me the fake passport..."
password = input ("Enter password to encrypt your message: ")
key= pad(password.encode(), 16)
cipher = AES.new(key, AES.MODE_ECB)
ct_bytes = cipher.encrypt(pad(secret_message, AES.block_size))
ciphertext= b64encode(ct_bytes).decode('utf-8')
print(f"the encrypted message is {ciphertext}")

Answer 1

Solution: Code has been modified to create a function to encrypt. The code along with output has been provided below. Comments have been added to depict the code.

 #Electronic Code Block AES algorithm, Encryption Implementation
from base64 import b64encode
from Crypto.Cipher import AES
from Crypto.Util.Padding import pad
from Crypto.Random import get_random_bytes

#Function Definition
def encryptECB(key,secret_message):
    cipher = AES.new(key, AES.MODE_ECB)
    ct_bytes = cipher.encrypt(pad(secret_message, AES.block_size))
    ciphertext= b64encode(ct_bytes).decode('utf-8')
    return ciphertext

#Main program calling the Function to encrypt
if __name__ == "__main__":
    secret_message = b" Please send me the fake passport..."
    password = input ("Enter password to encrypt your message: ")
    key= pad(password.encode(), 16)
    ciphertext =  encryptECB(key,secret_message)
    print(f"the encrypted message is {ciphertext}")

Output

Enter password to encrypt your message: pass
the encrypted message is uDJPxZw89nelPt2jlNtizVO1JEmN3wut7NlWXskVU/xdODW0POX+rmAV3q+vsuh3