AEX-NStep: Probabilistic Interrupt Counting Attacks on Intel SGX

To mitigate interrupt-based stepping attacks notably using SGX-Step, Intel introduced AEX-Notify, an ISA extension to Intel SGX that aims to prevent deterministic single-stepping. In this work, we introduce AEX-NStep, the first interrupt counting attack on AEX-Notify-enabled Enclaves. We show tha...