Studies of EPC encoding and privacy of RFID tag in traceability systems

RFID is a non-contact, multi-objective automatic identification technology, widely used in traceability from farm to supermarket. But standardization and privacy are the main problems to solve urgently for recent RFID traceability systems. In this paper, a standard format for the content of the RFID tags compliant with the EPCglobal standard is introduced, and the conversion between EAN-128 bar code and EPC code is presented. For privacy protection, EPC code is encrypted before written into the RFID tags, and then re-encrypted periodically. Encryption and re-encryption use the ElGamal cryptosystem. Finally, EPC encoding and re-encryption are implemented on Tag-it HF-I Transponder and ARM based on RFID readers, Montgomery's method and optimization are discussed for accelerating the computation of ElGamal, and the simulation results show that our plan is very effective.