IDEA.py

def idea_encrypt(plaintext, key):
    round_keys = generate_round_keys(key)
    plaintext_blocks = [plaintext[i:i + 8] for i in range(0, len(plaintext), 8)]
    ciphertext_blocks = []

    for block in plaintext_blocks:
        block = pad_block(block)
        data = bytes_to_int(block)

        data = initial_permutation(data)

        for round_key in round_keys:
            data = round_encrypt(data, round_key)

        data = final_permutation(data)

        ciphertext_blocks.append(int_to_bytes(data))

    return b''.join(ciphertext_blocks)


def generate_round_keys(key):


    round_keys = []
    for i in range(8):
        round_keys.append(bytes_to_int(key[i * 8:(i + 1) * 8]))

    return round_keys


def pad_block(block):
    return block + b'\x00' * (8 - len(block))


def bytes_to_int(data):
    return int.from_bytes(data, byteorder='big')


def int_to_bytes(data):
    return data.to_bytes(8, byteorder='big')


def initial_permutation(data):

    return data


def final_permutation(data):

    return data


def round_encrypt(data, round_key):

    return data ^ round_key

plaintext = b'LIfe is too harsh to live so uyou have to grind.'
key = b'SecretKey'

ciphertext = idea_encrypt(plaintext, key)

print("Original Plaintext:", plaintext)
print("Ciphertext:", ciphertext)