* @param $key Optional key, if none provided, a random key will be generated
* @return $encrypted Encrypted string
*/
* @param $key Optional key, if none provided, a random key will be generated
* @return $encrypted Encrypted string
*/
* @param $key Optional key, if none provided, a random key will be generated
* @return $str The unencrypted string
*/
* @param $key Optional key, if none provided, a random key will be generated
* @return $str The unencrypted string
*/