Reducing Power Side-Channel Information Leakage of AES Engines Using Fully Integrated Inductive Voltage Regulator

This paper demonstrates an integrated inductive voltage regulator (IVR) for improving power side-channel-attack (PSCA) resistance of 128-bit Advanced Encryption Standard (AES-128) engines. An inductive IVR is shown to transform the current signatures generated by an encryption engine. Furthermore, an all-digital circuit block, referred to as the loop-randomizer, is introduced to randomize the IVR transformations. A 130-nm test-chip with an inductive IVR with 11.6-nH inductance, 3.2-nF capacitance, and 125-MHz switching frequency is used to drive two different architectures of AES-128 engine: high performance and low power. The measurements demonstrate that the IVR with loop randomizer eliminates information leakage while incurring only 3% overhead in performance and 5% overhead in power over a baseline IVR-AES system. Moreover, while a key-byte can be extracted for the standalone high-performance and low-power AES (LP-AES) with only 5000 and 1000 measurements, respectively, the proposed IVR inhibits key extraction even with 500 000 measurements.