Face recognition is photographing an individual's face from different angles. This method is non-intrusive it does not require hands and has been generally accepted by users. A disadvantage may be that it is a little vague when different light exposure or may incorrectly identify an image or a mask. The voice recognition is exacerbating the pattern of a person's voice. The voice identification can be trusted, since it is a person's individual brand, but a voice can be recorded and played back later, you can alter with ...