Step by step example of a data being XORd with a multi-byte key

multi-xor.py

import binascii # This imports some functions used to convert data to hex values

data = "4d5a90000300000004000000ffff0000b8000000" # string representation of hex bytes start of executable file (notice the 4d 5a 'MZ' header).
text_key = "AABB" # string representation of the XOR key. This can be as long as you like

hex_data = (binascii.unhexlify(data)) # convert the data to Python hex type
hex_key = (binascii.unhexlify(text_key)) # convert the key to Python hex type


print(f"\nXOR Key is {hex_key}")
print(f"\nData to be encrypted is {hex_data}")
input("\nPress any key to encrypt each byte...")

encrypted = [] # set up a list to hold all our encrypted values

"""
Now we set up a loop to take the first byte of our data and XOR it against the bytes in the key.
If your key is 2 hex bytes long, then it will alternative between byte 1, then byte 2, then back to byte 1 as it XORs the bytes in our data
"""

for index,value in enumerate(hex_data):
    a = hex_data[index] ^ hex_key[index % len(hex_key)] # This is the actual encryption part which takes the hex byte of the data and XORs it with the alternating bytes of the key.
    encrypted.append(a) # This puts the encrypted hex byte into a final list
    input(f"\nPosition {index}: {hex(value)} is XORd with {hex(hex_key[index % len(hex_key)])} = {hex(a)}") # printing each encrypted value

print("\nThe final encrypted data is:")
print(f"\n{bytes(encrypted)}")