Application Agnostic EM Side-Channel Emanations of the FPGA Clock Distribution Network
FPGA electromagnetic leakage rose about 1.3 times when clock-resource use increased from 25% to 90%.
Electromagnetic side-channel analysis usually assumes a fixed implementation, which does not hold for reconfigurable FPGAs. The authors characterize clock-distribution emanations of deterministic finite state machines while varying placement, routing, and operating frequency. Raising utilized clock resources from 25% to 90% increased flagged high-activity grid points by 1.32 times in the mean-difference analysis and 1.39 times in the variance-difference analysis. The approach is application-agnostic and attributes leakage to clocking resources rather than one fixed circuit.
- FPGA reconfiguration invalidates fixed-circuit side-channel assumptions.
- The study varies placement, routing, frequency, and clock-resource use.
- Mean-difference flags rose 1.32 times from 25% to 90% clock use.
- Variance-difference flags rose 1.39 times over the same change.
Full article236 words · extracted from arxiv.org · click to collapse
Electromagnetic side channels have been extensively utilized in non-invasive attacks or analyses to extract critical information from deployed systems. Most of the attacks or analyses are typically executed on cryptographic algorithms under the assumption that the underlying implementation remains fixed. The assumption is valid in the context of fixed hardware, where modifications to the circuit are not made after manufacturing. However, in the case of adaptive hardware, including field-programmable gate arrays (FPGAs), the assumption no longer holds as modifications to the configuration of the array are permitted post-manufacturing. Consequently, this study introduces a methodology for the analysis of electromagnetic side channels of an FPGA through the study of deterministic finite state machines (DFSMs), where the effects of placement, routing, and operating frequency on the EM emanations of the FPGA due to the utilized clocking resources are characterized. To analyze the impact of frequency, device placement, and resource allocation on the EM emanations from the FPGA, statistical analysis including mean difference and variance difference calculations of measured EM fields were utilized to identify points of high EM activity on a set grid of sampled points. A 1.32x increase in flagged grid points was observed in the analysis of the mean difference when the percentage of utilized clock resources was increased from 25% to 90%. Similarly, a 1.39x increase in flagged grid points was observed when the variance difference was calculated for the same increase in clock resources.
Text extracted automatically; images, tables and formatting may be missing. Original: https://arxiv.org/abs/2609.33281