Power Analysis of FPGAs: How Practical is the Attack?

Abstract. Recent developments in information technologies made the secure transmission of digital data a critical design point. Large data flows have to be exchanged securely and involve encryption rates that sometimes may require hardware implementations. Reprogrammable de-vices such as Field Programmable Gate Arrays are highly attractive solutions for hardware implementations of encryption algorithms and several papers underline their growing performances and flexibility for any digital processing application. Although cryptosystem designers fre-quently assume that secret parameters will be manipulated in closed reliable computing environments, Kocher et al. stressed in 1998 that ac-tual computers and microchips leak information correlated with the data handled. Side-channel attacks based on time, power and electromagnetic measurements were successfully applied to the smart card technology, but we have no knowledge of any attempt to implement them against FPGAs. This paper examines how monitoring power consumption sig-nals might breach FPGA-security. We propose first experimental results against FPGA-implementations of cryptographic algorithms in order to confirm that power analysis has to be considered as a serious threat for FPGA security. We also highlight certain features of FPGAs that increase their resistance against side-channel attacks.