In spite of application potentiality of RFID technology is un-describable, the RFID system has several privacy related problems such as the data leakage and data traceability which should be resolved before its pervasive employment. For this reason, a security protocol for the RFID system protection is considered to be the best solution to prevent the privacy related problems. However, previously proposed protocols which are designed to prevent such privacy related problems still have leaved several problems un-resolved. In this paper, we proposed a security protocol which is based on one time pad scheme using random nonce and shared secret values. The protocol satisfies the security requirements and the low-cost implementation requirement. Moreover, we have proved the security correctness of the proposed protocol by using GNY Logic to guarantee that there is no design flaw in our protocol.