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 percent and over 92 percent 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.