Side-channel security of superscalar CPUs: Evaluating the Impact of Micro-architectural Features

Side-channel attacks are performed on increasingly complex targets, starting to threaten superscalar CPUs supporting a complete operating system. The difficulty of both assessing the vulnerability of a device to them, and validating the effectiveness of countermeasures is increasing as a consequence. In this work we prove that assessing the side-channel vulnerability of a software implementation running on a CPU should take into account the microarchitectural features of the CPU itself. We characterize the impact of microarchitectural features and prove the effectiveness of such an approach attacking a dual-core superscalar CPU