A method for storing a plurality of still images to form a panoramic image. The application protection method generates a key needed to execute the application which is provided to a user terminal using information on the user terminal, information on the application, and a part of text; and transmits the generated key to the user terminal. The switch is configured to such that when in a state associated with causing, or potentially causing, NBTI damage, both of the second pair of p-type transistors are in an OFF state for preventing NBTI damage thereto. The outer layer is made from material which is cut resistant thereby preventing the user’s hand from being cut or punctured and also preventing the heat resistant layer from being damaged.