With rapid developments of the mobile information technology, more and more related activities are carried out in the mobile device. Particularly, with rapid popularization of the mobile device such as the mobile phone and the tablet computer, more and more activities such as payment, identity authentication or the like are carried out in the mobile phone, the tablet computers or the like, and thus it becomes increasingly important to process secure payment and electronic business. Nowadays, various electronic password cards, USB keys or other devices have been widely applied to the computer system. However, in systems of the mobile phone and the table computer, the storage and encryption program of various electronic passwords are still relatively simple, which cannot meet a user's requirement for safety margin. Accordingly, how to achieve a high level of encryption in the mobile phone or other mobile devices will become a hot spot in the next period of time.
In daily life, things that carry out the identity authentication and the security encryption by using the biometric identification become more and more. For example, an access control system based on the fingerprint identification, a security system based on the iris identification, an identity authentication system based on the facial recognition, and so on. For another example, the identity authentication system based on the fingerprint identification is added to the current mobile phone. Specifically, the mobile phone is provided with a fingerprint identification assembly, and in most mobile phones, the fingerprint identification assembly is exposed outside an outer surface of the mobile phone, while occupying a large screen space. Problems relating to the use performance, the water proof performance, and the appearance aesthetics of the fingerprint identification assembly are urgent to be solved.