An apparatus and method for transmitting a plurality of key data. When a Short-Term Key Message (STKM) is received, a mobile equipment transmits the received STKM to a smart card. The smart card determines whether there are a plurality of key data in the STKM, detects the plurality of key data when there are the plurality of key data, generates individual information for identifying each of the plurality of detected key data, generates a response message having the plurality of detected key data and the generated individual information, and transmits the response message to the mobile equipment. Therefore, a plurality of key data can be included and transmitted in one message.