Bus Electrocardiogram: Vulnerability of SoC-FPGA Internal AXI Buses to Electromagnetic Side-Channel Analysis

Abstract

International audienceThis article demonstrates a confidential data vulner-ability in integrated circuits, especially in System-on-Chip (SoC)-field programmable gate array (FPGA) circuits. We demonstratethat the electromagnetic (EM) emanations of internal AdvancedeXtensible Interface (AXI) standard data buses are exploitable.Electromagnetic pulses recorded by a near-field probe in thevicinity of such data buses can be mapped to the underlying dataflux, just as an electrocardiogram (ECG) would map the heartactivity and blood circulation. This vulnerability is demonstratedby spying on the EM emanations caused by internal buseswhile MNIST handwritten digit images are sent through them.The transmitted MNIST data are found to be framed by pre-amble and post-amble signals enabling the detection of thetransmitted data themselves. Data (images, in this paper) arethen reconstituted by using a simple algorithm