def transform_int_list_to_hex_str(key_list):
    """
    Convert key from integer list to hex string.
    :param key_list: Input key as integer list
    :return: Key as hex string format
    """
    key_hex_str = ""
    for key_item in key_list:
        hex_str_item = format(key_item, 'x')
        if len(hex_str_item) == 1:
            hex_str_item = "0" + hex_str_item
        key_hex_str += hex_str_item
    return key_hex_str