A Security-Enhanced UHF RFID Tag Chip

The integration of strong security functionality to radio-frequency identification (RFID) tags operating in the ultra-high frequency (UHF) range is challenging. Main limiting factors are chip size and power consumption. In this work we present the design of the digital part of a security-enhanced UHF RFID tag that uses the Electronic Product Code (EPC) Generation-2 (Gen-2) standard for communication. The tag provides mutual-authentication functionality based on a challenge-response protocol and the Advanced Encryption Standard (AES). The stream cipher Grain is used for generating cryptographically secure random numbers during the authentication procedure. Moreover, the AES module on the tag has countermeasures integrated (shuffling of bytes and insertion of dummy rounds) to make so-called power analysis attacks less efficient. The digital part of the security-enhanced tag including AES and Grain modules can be implemented with 12000 GE (without non-volatile memory). The average power consumption during a full authentication round is 5 uW for a 130 nm low-leakage technology. The results clearly point out that both values chip size and power consumption fulfill the requirements of low-cost UHF RFID tags.