Exploiting Voltage Regulators to Enhance Various Power Attack Countermeasures

The security implications of on-chip voltage regulation on the effectiveness of various voltage/frequency scaling-based countermeasures such as random dynamic voltage and frequency scaling (RDVFS), random dynamic voltage scaling (RDVS), and aggressive voltage and frequency scaling (AVFS) are investigated. The side-channel leakage mechanisms of different on-chip voltage regulator topologies are mathematically analyzed and verified with circuit level simulations. Correlation coefficient between the input data and monitored power consumption of a cryptographic circuit is used as the security metric to compare the impact of different on-chip voltage regulators when implemented with the aforementioned countermeasures. As compared to a cryptographic circuit without countermeasure, the RDVFS technique implemented with an on-chip switched-capacitor voltage converter reduces the correlation coefficient over 80% and over 92% against differential and leakage power analysis attacks, respectively, through masking the leakage of the clock frequency and supply voltage information in the monitored power profile.