The experimental evaluation methodology consists of constructing implementations of the chosen cryptographic schemes, measuring physical emanations from these implementations, and using cryptanalytic algorithms to extract, from the recorded emanations, information that leaks from the innards of the implementations (e.g., secret keys). The experimental setup consists of three main modules, as depicted in Figure 1:
Figure 1 A Scheme of a typical implementation and flow chart of information extracting.
- Implementations of the cryptographic scheme, serving as test targets. This includes two variants:
- A pure software target implementation.
- A hardware implementation programmed into a dedicated device (e.g., FPGA chip or microcontroller mounted in an evaluation board). These hardware functions will be invoked by a control PC.
- Measurement setup, for acquiring emanations from the implementation:
- Probes (transducers), capturing physical emanations and representing them as analog electric signals.
- Signal conditioning (amplifiers and filters), converting the analog signal to usable levels and removing noise.
- Digital-to-analog conversion and signal processing (scope, spectrum analyzer) for acquiring information in digital form, and in particular, recording traces (time-dependent variation in the measured physical emanation during a single invocation of the implementation.
- A control PC for triggering and recording the traces.
- Cryptanalytic secret extraction:
- Algorithms for analyzing traces and extracting secret information from them, i.e., the secret keys used within the invocation of the implementation.
- A powerful computer cluster for executing these algorithms.
Figure 2 Parts of the measuring equipment and their relationships