def get_buckets(ciphertext, key_length):
    """Breaks ciphertext into buckets for each key character

    Args:
        ciphertext (int array): Array representing the ciphertext.
        key_length (int): The size of the key.

    Returns:
        Array of int arrays. Each int array represents parts of the ciphertext 
        corresponding to each key character.
    """
    return [ciphertext[i::key_length] for i in range(0, key_length)]