NFC (Near Field Communication) based applications are used in many areas. Widely usage of these systems requires utilizing of cryptography algorithms in order to solve security problems. NFC includes RFID (Radio Frequency Identification) tags in its structure. In this work, the main focus is to provide authentication between two RFID tags on FPGA. We adopt Identity Based Signature scheme based Authentication Protocol, and hardware/software co-design Authentication Protocol system is implemented on FPGA to use NFC systems securely. We show the implementation of digital signatures in RFID tags.