Reactive Design Strategies Against Fault Injection Attacks

In this chapter, we present to the readers two fault injection sensors against powerful fault injection techniques like laser and electromagnetic glitch. The first sensor is built upon a watchdog ring oscillator monitor with a standard Phase Locked Loop (PLL) block. Owing to the scarcity of PLL in resource-deficient devices, an all-digital alternative is proposed. The sensors are designed to be more reactive to fault injection methods than the sensitive target, in order to raise an alarm with solid security margin. Both countermeasures are low-cost and can be used to protect any arbitrary target circuit. Practical validation against near-infrared laser on Xilinx Virtex-5 FPGA is provided.