US Patent 9747597 Mobile device and authentication method for mobile payment system

A mobile device is utilized for a mobile payment system. The mobile device includes an identity module for storing an identity data; a communication module for communicating with a client and receiving a start signal to generate a notification signal; a processing module for executing an application program to obtain an authentication information according to the notification signal and determining whether the authentication information is legal according to a checking information to generate a switching signal; and a switching module for determining whether to connect the communication module and the identity module according to the switching signal; wherein the communication module reads the identity data stored in the identity module to obtain an identity result according to a conduction of the switching module, and transmits the identity result to the client.