Abstract:In order to effectively guarantee the safety of user’s privacy and data in RFID system, the distributed Challenge response authentication protocol is employed. The Elgamal password system and identification mechanism, and protocol of publicly verifiable threshold secret sharing will be applied to query and verify the label. This strategy not only offers reliable verification, but also protects the privacy of the user under search and the searching results. Analysis of the protocol’s safety and efficiency fins that the protocol is of high efficacy, sound security and excellent reliability.