Disclosed are a radio frequency identification (RFID) security apparatus and a method thereof. According to the RFID security method, a secure tag reader performs determining an AES key using security information received from a secure tag and generating an output key using the determined AES key, decrypting AES data received from the secure tag using the output key, and encrypting data to be transmitted to the secure tag using the output key and transmitting the data, and a secure tag performs generating an output key using an AES key and security information, and transmitting the security information to a secure tag reader, encrypting data to be transmitted to the secure tag reader using the output key, and transmitting the encrypted data to the secure tag reader, and decrypting data received from the secure tag reader using the output key.