Susceptibility of UHF RFID tags to electromagnetic analysis

The number of applications that use radio-frequency identification (RFID) technology has grown continually in the last few years. Current RFID tags are mainly used for identification purposes and do not include crypto functionality. Therefore, classical RFID tags are not designed as secure devices and do not contain countermeasures against side-channel analysis (SCA). The lack of such countermeasures makes RFID tags vulnerable to attacks relying on electromagnetic (EM) analysis. When attaching crypto functionality to future RFID tags which is considered for many use cases like forgery protection of goods, SCA becomes a concern. In this work we show the susceptibility of UHF RFID tags to EM analysis by using differential-EM analysis attacks. We have examined commercially-available passive UHF RFID tags with a microchip. The results show that a simple dipole antenna and a digital-storage oscilloscope connected to a computer are enough to determine data-dependent emanation of the microchip of passive UHF RFID tags at distances up to 1 m. Enhancement of RFID tags with crypto functionality therefore requires re-design of the whole tag architecture with respect to SCA.