A user terminal apparatus may include a communication unit for communicating with a server; a memory in which applications are stored; and a processor for executing an application including a first logic which requires security processing, performing mutual verification with the server, controlling the communication unit such that a request for executing the first logic on the server is sent to the server, and when the execution result of the first logic is received from the server, proceeding with the execution of the application by using the received execution result.