Recently, many aspects of the security in RFID systems has become a subject of prime attention. RFID technology has been applied heavily for its small size, low cost, and ability to stores large amounts of data. However, the features in RFID technology, such as unique identification and out-of-sight readability, can also bring about some security concerns. In this thesis, we address the tracking issue of RFID tags and propose a protocol to perform authentication while preserving the privacy of its user.