In RFID applications, there are situations where RFID tags can be grouped and numbered continuously in a group. Aiming at such applications, the group-based polling anti-collision algorithm for RFID tag identification is proposed. To solve the security problem in data communication between RFID reader and tags, several common security protocols are analyzed, and the advantages and disadvantages of each protocol are discussed, respectively. Based on grouped tags and re-encryption scheme, a security protocol for RFID tags data transmission is proposed. The method of applying re-encryption scheme and the execution process of the security protocol are described in detail. Through analyzing the security of the proposed protocol from different aspects such as anti-tracking, anti-tamper and anti-counterfeiting, it can be shown that the proposed protocol provides good security for the transmission of RFID tags data, and supports low capability RFID tags and fast reading and writing tags information.