Hardware Information Flow Tracking

Information flow tracking (IFT) is a fundamental computer security technique used to understand how information moves through a computing system. Hardware IFT techniques specifically target security vulnerabilities related to the design, verification, testing, manufacturing, and deployment of hardware circuits. Hardware IFT can detect unintentional design flaws, malicious circuit modifications, timing side channels, access control violations, and other insecure hardware behaviors. This article surveys the area of hardware IFT. We start with a discussion on the basics of IFT, whose foundations were introduced by Denning in the 1970s. Building upon this, we develop a taxonomy for hardware IFT. We use this to classify and differentiate hardware IFT tools and techniques. Finally, we discuss the challenges yet to be resolved. The survey shows that hardware IFT provides a powerful technique for identifying hardware security vulnerabilities, as well as verifying and enforcing hardware security properties.