Passive RFID transponder with power-aware encryption

A passive RFID transponder with power-aware encryption is developed to address security under available power. This transponder includes an RF front-end module, a signal processing unit and a power-aware security module. In this power-aware security module, the Advanced Encryption Standard (AES) is adopted at 128 bits where the manners of encryption transformations are dynamically adapted according to available power. Additionally, serial input and output are implemented in the power-aware security module to minimize hardware and connection complexities. Particularly, varied frequencies and redundant bits are also employed in the encrypted data from AES to enhance security. As compared the conventional transponders, the proposed transponder can effectively use power to do and vary encryptions. Furthermore, this power-aware mechanism can be a plus to security.