Design and Implementation of a Waveform-Matching Based Triggering System

Implementation attacks such as side channel attacks and fault attacks require triggering mechanisms to activate the acquisition device or fault injection equipment. Most academic works work with a very simple and reliable trigger mechanism where the device under test itself provides a dedicated signal. This however is not possible in real attack scenarios. Here the alternative is to use IO signals or coarse features of the side channel signal (co-processor switches on, power consumption goes up) for triggering. However, fault injection in particular requires very accurate timing. Our work deals with the many scenarios where such simple triggering mechanisms are not available or not effective. We present our design, architecture and FPGA implementation of a waveform-matching based triggering system. Our configurable trigger box is able to sample and match an arbitrary waveform with a latency of 128 ns. We provide results of our experimental evaluation on devices and side channel signals of different nature, and discuss the influence of several parameters.