Strong Crypto for RFID Tags - A Comparison of Low-Power Hardware Implementations

The implementation of security protocols in RFID systems is challenging because of the fierce constraints concerning power consumption and low die size of RFID tags. The choice of the appropriate cryptographic primitive is difficult because there are many different algorithms available and the design options for each are manifold. In this paper, we analyze the standardized cryptographic algorithms SHA-256, SHA-1, MD5, AES-128, and ECC-192 in terms of implementation efficiency. The three parameters mean power consumption, chip area, and the number of clock cycles, are used to introduce a metric for a fair comparison of different hardware implementations. We describe the implementations of the five modules which were optimized for application in passive RFID tags and compare their results. We give conclusive evidence that the use of AES in RFID systems is most appropriate today.