Provided is a method of efficiently processing a Short-Term Key Message (STKM) in the mobile broadcast supporting the mobile terminal. A structure of a response message according to processing the STKM in the smart card is also provided. In particular, a variety of information necessary for reproducing in the player is included in the response message and delivered to the mobile terminal, thereby the mobile terminal can easily obtain the desired information through the response message. Therefore, when the STKM is processed in the mobile terminal, there is no need to process operations except for a resending check, and the information does not need to be stored separately.