A First Study of Compressive Sensing for Side-Channel Leakage Sampling

An important prerequisite for Side-Channel Attacks (SCA) is leakage sampling where the side-channel measurements (i.e. power traces) of the cryptographic device are collected for further analysis. However, as the operating frequency of cryptographic devices continues to increase due to advancing technology, leakage sampling will impose higher requirements on the sampling rate and storage capacity of the sampling equipment. This paper undertakes the first study to show that effective leakage sampling can be achieved without relying on sophisticated equipments through Compressive Sensing (CS). As long as the information is leaked in the low frequency component, CS can obtain low-dimensional samples by simply projecting the high-dimensional signals onto the observation matrix. The power traces can then be reconstructed in a workstation for further analysis and storage. With this approach, the sampling rate to obtain power traces is no longer limited by the operating frequency of the cryptographic device and Nyquist sampling theorem. Instead it depends on the sparsity of the leakage signal. As such, CS can employ a much lower sampling rate and yet obtain equivalent leakage sampling performance, which significantly lowers the requirement of sampling equipments. The feasibility of our approach is verified theoretically and through experiments.