Abstract: According to the particularity of search protocol for RFID,its security requirements were extended in this paper．Then,on the basis of the extended security requirements,some security enhancements and improvements on the original SSP protocol were achieved,and a secure anti-collision search protocol for RFID called SSP＋protocol was proposed．Subsequently,based on security analysis of SSP＋protocol,it was proved that this improved protocol can not only provide general security requirements,such as privacy protection,anonymity,untraceability,but also eliminate security risk caused by collision,thereby meeting anti-collision that is the unique security requirement on search protocol．

Key words: Radio frequency identification (RFID),Search protocol,Security,Anti-collision