Designing and Implementing Malicious Hardware

Hidden malicious circuits provide an attacker with a stealthy attack vector. As they occupy a layer below the entire software stack, malicious circuits can bypass traditional defensive techniques. Yet current work on Trojan circuits considers only simple attacks against the hardware itself, and straightforward defenses. More complex designs that attack the software are unexplored, as are the countermeasures an attacker may take to bypass proposed defenses. The authors present the design and implementation of Illinois Malicious Processors (IMPs). There is a substantial design space in malicious circuitry; they show that an attacker, rather than designing one specific attack, can instead design hardware to support attacks.