Backward-Edge Control Flow Integrity Based on Return Address Encryption

Control flow integrity (CFI) plays an important role in defending against code reuse attacks (CRA). It protects the program’s control flow from being hijacked by restricting control flow transfers during execution. Specifically, backward-edge CFI safeguards return addresses to mitigate Return-Oriented Programming (ROP) attacks. In this work, we implement a backward-edge CFI mechanism that employs the Advanced Encryption Standard (AES) for cryptographic protection of return addresses. We utilize the gem5 simulator for architectural modeling and evaluation. Additionally, we design a dedicated AES hardware accelerator and integrate it into the system through gem5+RTL co-simulation. The AES accelerator is synthesized under TSMC 28 nm technology, which can work at 1GHz, with an area of 10045 μm² and a power consumption of 1.31 mW. Experimental results indicate that the performance overhead of the backward-edge CFI scheme is less than 0.1%.