Abstract: The method of implementation of security and privacy in low cost tags is a key technique which needs to be solved in research field. Based on the use of partial ID, CRC checksum and dynamic update ID, this paper proposes a new RFID mutual authentication protocol which possesses forward security ability and can defeat location privacy attack, relay attack, eavesdropping attack and denial-of-service attack. The new scheme conforms to EPC Class1 Gen2 standards and effectively solves problems of RFID security and privacy with lower complexity of hardware, so it is useful for low cost RFID tags.