Nonlinear Code-Based Low-Overhead Fine-Grained Control Flow Checking

A hardware-based control flow monitoring technique enables the detection of errors in both the control flow and the instruction stream executed on a processor. However, as shown in recent publications, these techniques fail to detect malicious carefully-tuned manipulations of the instruction stream in a basic block. This article presents a non-linear encoder and checker that can cope with this weakness. It is a MAC based control flow checker that has the advantage of working with basic blocks of variable length, can detect every error, and performs the computation in real-time. The architecture can easily be modified to support different signature size and error masking probabilities.