Mobile device for processing application of client device and method for processing application of client device using the same

A method for processing an application of a client device, the method comprising:

• the client device receiving an image signal or an audio signal converted from application information including one or more of electronic signature requirement, payment requirement, or user authentication requirement from a web service device;
• the client device receiving an image signal or an audio signal converted from the application information and playing the received image signal or the audio signal;
• a mobile device acquiring the played image signal or the audio signal ;
• the mobile device converting the acquired image signal or the audio signal into the application information;
• the mobile device executing and processing at least one application of electronic signature, payment, or user authentication according to the content of the application information;
• and
• the mobile device executing and processing the application to provide the result of processing the application to the web service device.